Proposal summaries

These are research proposals that have been approved by the ALSPAC exec. The titles include a B number which identifies the proposal and the date on which the proposals received ALSPAC exec approval.

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B1007 - Childhood obesity and severe antenatal maternal stress - 15/06/2010

B number: 
B1007
Principal applicant name: 
Dr Kathryn Abel (University of Manchester, UK)
Co-applicants: 
Dr Louise Howard (King's College London, UK), Dr Nic Timpson (University of Bristol, UK), Prof Gene Feder (University of Bristol, UK)
Title of project: 
Childhood obesity and severe antenatal maternal stress
Proposal summary: 

Childhood Obesity and Severe Antenatal Maternal Stress

Obesity is a complex public health problem that is a growing threat to children's health, as well as a current and future drain on National Health Service (NHS) resources. Obesity already costs the NHS directly around £1 billion a year and the UK economy a further £2.3 to £2.6 billion in indirect costs. If this present trend continues, by 2010 the annual cost to the economy could be £3.6 billion a year.

By the IOTF's international standards nearly 27.5% of girls and 22% of boys in UK aged 2-15 were found to be overweight, including 5.5% of boys and 7.2% of girls who were obese in 2002. The IOTF analysis indicates a marked acceleration in the trend from the mid-1980s onwards. Using the national Body Mass Index percentiles approach (adopted by the Department of Health assuming 15% overweight including 5% obesity in 1990) 30.7% of girls and 30.3 % of boys were overweight, including 16% who were obese, by 2002.(See DH weblink)Furthermore, childhood obesity is one of the key predictors of adult obesity. Evidence of the long term effectiveness of obesity interventions is mixed (see Mend website; ) once obesity is established (see Oude Luttikhuis et al 2009). Identifying early risk factors for child obesity may have important preventive implications for future public health strategy.

In humans, adverse early life experiences such as childhood trauma, neglect and abuse are associated with the development of psychosocial disorders (Heim & Nemeroff, 1999; Kaufman et al., 2000; Heim et al., 2002; MacDonald et al., 2008). In animal models, an adverse early life experience causes abnormalities in neurodevelopment (Pickering et al., 2006), increased stress response as measured by plasma corticosterone (Meaney et al., 1993; Pihoker et al., 1993), and behavioural deficits (Pryce and Feldon, 2003; Pryce et al., 2005; Slotten et al., 2006) in adulthood.

Numerous studies report relationships between palatable food (rich in sugar and saturated fat), and emotional states and stress. In humans and in animal models, emotions influence food intake and choice of food and palatable foods high in fat and carbohydrate improve mood and modify stress responsivity. For example, subjects report a preference for palatable food rich in saturated fat and sugar during negative emotions (Macht, 2008) and adult individuals subjected to psychological stress in a laboratory setting are reported to eat greater amounts of palatable food compared to control groups (Oliver et al., 2000). In adults, depression and anxiety can also be linked to compulsive behaviours and craving for palatable food which induce feelings of pleasure (Kelley et al., 2005; Paterson and Markou, 2007). A study in UK school children reported that higher self-reported stress scores were associated with increased intake of fatty food compared to fruits and vegetables (Cartwright et al., 2003). These data suggest that the direction of the association is that humans subjected to stressful circumstances (chronically and acutely) are more likely to crave palatable, high saturated fat and high sugar containing foods or 'comfort foods'.

Dallman (2005) described the phenomenon of 'comfort food' or 'comfort eating' as self-medication with food.Adam and Epel, 2007 propose that stress-stimulated consumption of palatable food is a form of reward-based eating because palatable high-fat diet or 'comfort food' modulates hypothalamic-pituitary-adrenal (HPA) axis activity and indirectly blunts the stress response. In other words, the craving for such foods derives from their effect on the HPA axis which the presence of the stress has activated acutely or chronically. Animal data support the notion that consuming such a diet can have a beneficial effect by modulating the stress response: rats consuming molar sucrose solution and sweetened vegetable shortening (lard), in addition to regular chow, showed attenuated ACTH responses to restraint stress and lower plasma corticosteronecompared to those consuming chow alone (Pecoraro et al., 2004;la Fleur 2005). Similarly, rats exposed to lard for 2 h per day for 7 weeks also showed a decreased stress response compared to rats consuming chow only (Kinzig et al., 2008). Alterations in hippocampal GR mRNA and hypothalamic CRH mRNA, key mediators of HPA axis activity, are thought to be the mechanisms by which these diets alter the stress response (e.g. Morris 2010). Thus, data suggest that palatable high fat diets or comfort food have a role in ameliorating stress and possibly stress-related behaviour whether given chronically or as an option.

These studies focus on postnatal events in humans and animal models. It is well recognised that prenatal maternal stress alters HPA axis sensitivity in rodent models (e.g. Kapoor et al 2008; Liu et al 1997). Our work and others has provided evidence that in utero exposure to severe maternal stress can increase the risk of neuropsychiatric disorder i.e. schizophrenia and affective disorder (Khashan et al 2008; Khashan et al submitted) both of which are considered in part to result from altered HPA axis sensitivity.

Research Question

Does pregnancy-related and early postnatal exposure to domestic violence predict increased BMI in offspring of exposed mothers in the ALSPAC cohort?

Hypotheses

Primary hypothesis: a child exposed to severe early life stressors is more likely to become overweight or obese than children not exposed in this way manifest as a rightwards shift in the BMI (and or DXA derived fat mass) distribution by age 15 of exposed versus unexposed children.

Secondary hypotheses: i) as a result of exposure to maternal stress in utero, HPA axis sensitivity in exposed children is greater than in unexposed children (tested using salivary cortisol measures) ii) overweight or obesity occurs through increased intake of palatable or comfort foods in exposed versus unexposed children iii) intake of a high saturated fat and high carbohydrate diet reduces or modulate HPA axis sensitivity iv) overweight or childhood obesity is associated with reduced HPA axis sensitivity (mean salivary cortisol levels) in exposed children compared to exposed non-obese or normal weight children

Future hypotheses i) We will examine whether we may use birth weight (BW) of children exposed and unexposed as a proxy for early life stress. We would then examine BW and its association with later life BMI through the use of genotypes associated with it via the presence of key genetic loci associated with birth weight(Freathy et al 2010).

Method

We wish to use a model of early life stress indexed by the maternal experience of adverse life events and of domestic violence before conception, during pregnancy or in the first year of life, in order to assess effects on childhood growth and rates of overweight and obesity. We shall examine the distribution of the BMI and body composition (DXA) of children exposed in utero and postnatally to maternal domestic abuse and compare it to that of unexposed children and assess HPA axis sensitivity using salivary cortisol levels in obese/overweight and normal weight exposed children. Variables assigning abuse status to individual participants have already been derived (see below) and we seek permission to examine these in light of anthropometric, serological and genetic data.

All analysis will be undertaken collaboratively by Nic Timpson at the MRC CAiTE centre and as such we have not requested data transfer.

Exposure variables: Antenatal domestic violence has been assessed in the ALSPAC cohort at 18 weeks gestation. Participants were asked two questions on whether their partner had been emotionally cruel, and whether their partner had physically hurt them since the start of the pregnancy and to state how much it affected them on a scale from 'no effect' to 'affected a lot'. A woman will be considered to have experienced antenatal domestic violence if she responded positively (any level of effect) to either physical or emotional cruelty since the start of the pregnancy. Questions asking if their partner had been emotional or physically cruel have also been used to define postnatal domestic violence and this was reported at 2, 8, 21 and 33 months after the child was born, in each case referring to the period since the last questionnaire. Violence from the partner to the mother, partner to the child and mother to the child was reported by the mother in the same way at these times. The repeated responses will be summarised into a variable indicating the number of time points that violence was experienced since the birth, a separate variable for each of: violence occurring to the mother, to the child from partner or child from the mother. Other stressful life events will be assessed using the life events scale covering 13 life events including serious illness/death in the family, marital difficulties, financial problems etc. These were recorded by the mother at 8, 21 and 33 months after the birth.

Outcome variables:

Child Biometric Data: Information collected on birthweight and gestational age will be used along with the height, weight, ethnicity of the mother and parity of the child, to determine the birthweight centile of the child using the Gestation Network calculator; children in the lowest 10% will be counted as small for gestational age (SGA).BMI recorded atages21 months, 4, 7, 9, 11 and13 years of age usingheight and weight measurements in GP reports; as well asDXA fat mass at the same ages.

HPA axis sensitivity: we shall use salivary cortisol measures collected at ages xxx and compare mean and SD between exposed and unexposed children. (need to check availability).

Dietary records at age 10 yrs will be used to account for dietary/calorie intake.

Potential confounders: The following maternal characteristics will be measured as potential confounders of any association between stressors and child biometric measures: maternal age at the birth of the child, maternal socioeconomic status as assessed by the following variables: maternal education, (recorded at 32 weeks gestation simplified from a 5 item response into 3 categories: low (CSE, vocational), medium (O-level), high (A-level, degree)) and homeownership status, grouped as: own/mortgage versus rented (Cleland et al 2010; Crawford et al 2010). Smoking and alcohol use during pregnancy were determined at 18 weeks gestation. Women are considered to have smoked during pregnancy if they had smoked any form of tobacco in the 2 weeks prior to completion of the 18 week questionnaire. Women were also questioned on their alcohol use during pregnancy at 18 weeks gestation, responses were categorised into less than 1 glass (unit) per day and 1 or more glasses (units) per day.

Analysis

Simple analyses will be used to assess the association between severe early life stress exposure, measured at 18 weeks gestation and up to 33 weeks postnatally, and the biometric outcome variables.Multivariable analysis will be conducted using logistic regression to adjust for the following possible confounding factors: SES (maternal education, homeownership status), maternal marital status, maternal age, parity, ethnicity and paternal depression. Biometric variables will be handled as continuous variables initially to look for shifts in the distribution of weight in the exposed and unexposed groups by age. Bivariable associations between overweight, antenatal domestic violence and baseline characteristics of the mother and child will be assessed using chi-squared or t-tests. The association between antenatal domestic violence and child overweight will be further investigated using logistic regression. Generally, the data will be analysed in three stages: (i) calculation of unadjusted odds ratio of severe early life stressor (domestic violence and life events score) in relation to overweight; (ii) adjustment for possible confounding factors; (iii) addition of potential mediators to the model. To investigate the possible mediating effect of maternal depression on the association, mother with recorded depression (EPDS score greater than 13) will be excluded in a sensitivity analysis. A variable for domestic violence exposure i.e. no violence, antenatal violence only, antenatal and postnatal violence, postnatal violence only, will also be used to give a direct comparison of the different levels of exposure. If numbers are sufficient, gender interactions will also be explored.

A second set of analyses using a Chi square tests will assess the secondary hypotheses: the relationship between exposure and mean salivary cortisol levels. The divide the cases into exposed overweight/obese and exposed normal weight and

Multivariable analysis will be conducted using logistic regression to adjust for the following possible confounding factors: SES (maternal education, homeownership status), maternal marital status, maternal age, parity, smoking, ethnicity and paternal depression. Bivariable associations between salivary cortisol levels, antenatal domestic violence and baseline characteristics of the mother and child will be assessed using chi-squared or t-tests. The association between antenatal domestic violence and childhood salivary cortisol levels will be further investigated using logistic regression. Finally, dietary intake will be assessed as high or low in palatable food and/or calorie and a chi square test used to examine the association between maternal stress/domestic violence and dietary intake. Multivariable analysis will be conducted using logistic regression to adjust for the following possible confounding factors: SES (maternal education, homeownership status), maternal marital status, maternal age, smoking, parity, ethnicity and paternal depression.

Missing Data: We shall use the (MICE) with the ice command in Stata to impute missing values using chained equations. This will be carried out on the full dataset including all variables used in this analysis as well as additional variables known to be related to non-response.

Date proposal received: 
Tuesday, 15 June, 2010
Date proposal approved: 
Tuesday, 15 June, 2010
Keywords: 
Depression, Endocrine, Obesity, Weight
Primary keyword: 

B1010 - Economic determinants of conduct disorder and oppositional defiance disorder - 14/06/2010

B number: 
B1010
Principal applicant name: 
Dr Ellen Meara (Harvard Medical School, Boston, USA)
Co-applicants: 
Niels Rosenquist (Not used 0, Not used 0), Ezra Golberstein (Not used 0, Not used 0)
Title of project: 
Economic determinants of conduct disorder and oppositional defiance disorder
Proposal summary: 

Project outline: The Economic Determinants and Costs of Delinquent and Disruptive Behavior

Motivation:

Disruptive and delinquent behavior in children and adolescents is a strong predictor of anti-social and

criminal behavior later in adults. (Sentence on Criminality Rates) While there is a large literature on the

development ofthese traits, risk factors for these traits, and evidence of efficacious treatment to prevent

these behaviors, the use of evidence based interventions is very low as practiced in communities within

major countries like the United States and the United Kingdom. There is debate over what role economic

policy might play in addressing this issue.

Research Plan:

Our group, a task force of Harvard's Center for the Developing Child, has been asked to perform analyses

that show how public policy can impact the development of delinquent and disruptive behavior, as well as

the economic costs of these traits to society. We seek to collaborate with (and support) ALSPAC

researchers in a study of the economic antecedents of and costs from disruptive and delinquent behavior.

Utilizing multiple data sources (including the Add Health and NLSY cohort data in our possession) we

seek to look at "natural" economic experiments where exogenous changes in public policy might impact

the development of these traits. We also seek to estimate the life-long costs to society of individuals with

these traits.

Research Aims:

Aim 1:

Determine the role that changes in economic policy might have on the development of disruptive and

delinquent behavior, as defined by standard research practice from survey responses. These policies

include

a. Health insurance coverage for parents and their children

b. Insurance design to improve access to evidence-based treatment for co-occurring

disorders (i.e. ADD, depression)

c. Welfare poliCies

d. School reforms, including special needs education

To control for endogeneity in outcomes, we propose to use two forms of randomization based on the

various strengths of the available datasets. First, we plan to utilize specific genetic variants linked with

these traits, controlling for parental genotype when possible. Second, we will use variation across time

and geographic areas in welfare, health insurance, and related variables that affect prevention of CD/ODD

and the effective treatment of these disorders. Finally, we hope to interact these policy changes with

temperament measures as a way of understanding individual traits.

Aim 2:

Determine the cost of delinquency and disruptive behavior. We seek to estimate the suspected cost to

society of children who meet criteria for oppositional defiant disorder and conduct disorder, by looking at

predicted future rates of incarceration and health care costs (particularly mental health) thru linking

childhood measures of disruptive and delinquent behavior with future criminal activity and other

economic measures.

Needs from ALSPAC data (primarily to serves as controls for our results):

1) Longitud inal measures of parental inputs (including parenting styles)

2) School -level traits, including data on peer groups

3) Estimates of anti-social behavior in children

5) Targeted SNP-level data for a limited set of markers (MAO-A, primarily)

6) Reported health care utilization and youth services intervention(s) for the sample, including

detailed information on use of behavioral and pharmacological treatments of ODDleD and

related disorders.

Date proposal received: 
Monday, 14 June, 2010
Date proposal approved: 
Monday, 14 June, 2010
Keywords: 
Primary keyword: 

B1008 - A Behavioral Genetics Approach to Emotion Recognition Accuracy - 13/06/2010

B number: 
B1008
Principal applicant name: 
Dr Hillary Anger Elfenbein (Washington University of St Louis, USA)
Co-applicants: 
Title of project: 
A Behavioral Genetics Approach to Emotion Recognition Accuracy
Proposal summary: 

The goal of this project is to take a behavioral genetics approach to skill in emotion recognition accuracy. The ALSPAC team provided its participants with Dr. Stephen Nowicki's emotion recognition test called the Diagnostic Analysis of Nonverbal Accuracy (DANVA), in which respondents judged the emotions contained in facial expressions and vocal tones. Children completed this diagnostic during the Focus@8 session, and Main Carers completed this diagnostic in the Teen Focus 1 or Teen Focus 1 FastTk session. I propose to conduct two analyses of these existing data:

1. Convergence among twins

This analysis would compare the correlation of scores among Monozygotic twins (identical twins who share 100% of the same DNA) versus Dizygotic twins (fraternal twins who share 50% of their DNA). Greater convergence for MZs than DZs would suggest that there is a biological component to the development of emotional skill.

For this analysis, we would need to be able to identify who are the 195 pairs of twins (this number of twins was reported by the ALSPAC team, e.g., http://www.bristol.ac.uk/alspac/sci-com/resource/recruit/). For each of these 195 pairs of twins, we would also need to be able to identify whether they are identical/MZ or fraternal/DZ. (This determination of MZ vs. DZ could be made using genetics data if it has not already been done for other purposes.)

2. Convergence between main carers and children

This analysis would establish the correlation of scores between children and their main carers. It would be valuable to identify which carers were biologically related vs. unrelated to the children, and to compare the magnitude of correlations for each type. If there is a sufficient number of biologically unrelated carers to make the comparison, greater convergence among related vs. unrelated carers would suggest that there is a biological component to the development of emotional skill. Even if there is not a sufficient number of biologically unrelated carers, the correlation between children and their main carers would be a valuable descriptive statistic that could be compared with the correlation for fraternal/DZ twins, given that both types of relatives share 50% of their DNA.

Control variables: For the above analyses, it would be valuable to include control variables of the sex of the child, their ethnicity, and their income / socio-economic status.

Date proposal received: 
Sunday, 13 June, 2010
Date proposal approved: 
Sunday, 13 June, 2010
Keywords: 
Depression, Genetics, Mental Health
Primary keyword: 

B1009 - Differences in ADL IQ and academic achievement between children with moderate and severe co-ordination difficulties - 11/06/2010

B number: 
B1009
Principal applicant name: 
Dr M M Schoemaker (Centre for Human Movement Sciences, University Medical Centre Groningen, Netherlands)
Co-applicants: 
Dr R P Lingham (Not used 0, Not used 0), Prof Dr M J Longmans (Not used 0, Not used 0), Prof Alan Emond (University of Bristol, UK)
Title of project: 
Differences in ADL, IQ and academic achievement between children with moderate and severe co-ordination difficulties
Proposal summary: 

Differences in ADL, IQ and academic achievement between children with DCD and children at risk for DCD.

Study Team:

Dr. M.M. Schoemaker, Associate Professor in Human Movement Science, University of Groningen, The Netherlands.

Dr Raghu Lingam Lecturer in Community Child Health University of Bristol

Professor M.J. Jongmans, Department of Pediatrics, University Medical Centre Utrecht, The Netherlands

Professor Alan Emond, Professor of Child Health University of Bristol

Background

Developmental Coordination Disorder (DCD) is a frequently occurring disorder in childhood with a prevalence ranging between 1.4 and 19%. In order to be classified as DCD, children need to meet four diagnostic criteria as listed in the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV-TR, 2000). According to criterion A of the DSM-IV Criteria for DCD, children only meet this criterion if they have a significant impairment in motor coordination development, which interferes with academic achievement and/or activities of daily living (ADL). Over the years, various cut-off criteria have been applied to separate children with motor difficulties from typically developing children, varying from the 5th to the 20th centile. Recently, more strict inclusion criteria for the condition have been defined in the Leeds Consensus Statement (LCS, 2006). Children with scores below the 5th centile on an individually administered motor coordination test fulfill Criterion A; however those children between the 5th and 15th centile are said to have "probable" coordination difficulties and said to be at risk of DCD. Application of the more strict criteria as proposed by the LCS in the ALSPAC study, has recently led to a prevalence of 1,8% (Lingam et al., 2009).

Although a large group of clinicians and researchers have consented with the use of the 5th centile as cut-off criterion, it is acknowledged that this cut-off criterion is arbitrary and merely defined on statistical grounds. But as resources are limited for children with developmental problems, it is legitimate to offer those services in particular to those who are most severely in need of them. At present, in the UK more intensive services are provided for children with scores on a motor coordination test below the 5th centile than to those with scores between the 5th and 15th centile. The underlying assumption is that motor performance of children with scores below the 5th centile will interfere more with their academic achievement and ADL than those with less severe motor difficulties. However, this assumption is not evidence based. The decision to use the 5th centile as cut-off criterion will be more empirically grounded, if it is supported by research findings.

The data of the ALSPAC population based study offers an ideal opportunity to investigate whether children with more severe coordination difficulties are indeed the ones with the most severe problems in areas of academic achievement and/or ADL. In the ALSPAC study, 7,058 7 to 8 year old children were assessed with the ALSPAC coordination test, which was derived from the Movement Assessment Battery for Children. With this test, 324 children were identified as children with severe coordination difficulties (scores below 5th centile), and another 975 children were identified as children with moderate coordination difficulties (scores between 5th and 15th centile). Data regarding handwriting and reading, as measures of academic achievement, IQ as well as ADL were gathered for all of these children in the ALSPAC study, which enables a comparison of both groups of children regarding the amount of interference of the motor difficulties on the core aspects of the disorder. The large sample of children in ALSPAC offers sufficient statistical power to answer the research question in a reliable way.

Research question:

Are children with severe coordination difficulties (scores on coordination test below 5th centile) more impaired on measures of ADL and academic achievement than children with moderate coordination difficulties (scores on coordination test between 5th and 15th centile)?

Methods:

Participants:

The sample will consist of 6990 7-8 year old children who were assessed with the ALSPAC coordination test and who completed the ADL questions or handwriting test. Children with known visual, developmental, or neurologic condition will be excluded as well as children with an IQ less than 70. The ALSPAC coordination Test will be used to divide the sample into three groups: a group of children without coordination difficulties (scores on coordination test above the 15th centile), a group of children with moderate coordination difficulties (scores on coordination test between 5th and 15th centile) and a group with severe coordination difficulties (scores on coordination test below 5th centile).

The three groups of children will be compared on the following outcome variables:

Measure of ADL

ADL derived variable

Measures of academic functioning:

- Language (Wechsler Objective Language Dimensions-WOLD)

- Spelling (Nunes & Bryant)

- Reading (NARA-II and Wechsler Objective Reading Dimensions -WORD)

- Short-term memory (Children's Test of Nonword repetition)

- non-verbal skills (Diagnostic Analysis of Nonverbal Accuracy Scale-DANVA)

- IQ (WISC-III)

- attention/concentration (Development and Well-Being Assessment-DAWBA)

Analysis of variance will be carried out to investigate a main effect of group division, followed by post-hoc analyses to investigate differences between specific groups. Regression methods will account for potential confounding and mediating factors identified from the literature. Adjustment will be made for the bias introduced by missing data using multiple imputation by chained equation.

Power calculation:

The prevalence of motor coordination difficulties has been reported to be around 5% in literature. Taking 7000 to be the study population (approximate children that attended focus at 7) and our outcome variable to be the lowest 10% of a given developmental trait, the relative risk that it will possible to be 80% sure of detecting at the 5% level of significance is 1.59.

Date proposal received: 
Friday, 11 June, 2010
Date proposal approved: 
Friday, 11 June, 2010
Keywords: 
Depression, Mental Health, Neurology, Violence
Primary keyword: 

B1002 - The effect of breastfeeding on health and developmental outcomes an instrumental variable approach - 03/06/2010

B number: 
B1002
Principal applicant name: 
Emla Fitzsimons (Not used 0, Not used 0)
Co-applicants: 
Dr Marcos Vera-Hernandez (Not used 0, Not used 0)
Title of project: 
The effect of breastfeeding on health and developmental outcomes: an instrumental variable approach
Proposal summary: 

The effect of breastfeeding on health and developmental outcomes: an instrumental variable approach

by

Emla Fitzsimons, Senior Research Economist, Institute for Fiscal Studies

Marcos Vera-Hernandez, Economics Lecturer, University College London

The causal effects of breastfeeding on children's outcomes such as health and cognitive development are little understood. The problem is that breastfeeding is a choice made by parents, and so any associations between breastfeeding and outcomes may be confounded by broader socio-economic factors. Even if we control for these as best we can, there is still the concern that there are unobserved factors that simultaneously affect the decision to breastfeed and children's outcomes.

If well conducted, randomized trials are known to provide the most robust evidence on causal effects. However, a breastfeeding randomized trial would probably be very costly and unethical. In the absence of a randomised controlled trial, economists have long turned to the method of instrumental variables in order to identify causal effects. It is a technique that recognises that breastfed and non-breastfed children would have different average outcomes even regardless of whether or not they were breastfed, most likely because they differ in background characteristics. This technique works by assumming that there is one variable, called an instrumental variable, that (1) predicts breastfeeding participation, (2) only affects outcomes through affecting breastfeeding, and (3) is not correlated with the unobserved background characteristics that affect outcomes. The credibility of the resulting estimate thus hinges on the instrument being suitable. We believe that day of birth satisfies all of these requirements. Our hunch is that it satisfies (1) because day of birth impacts on the amount of breastfeeding support/advice received whilst in hospital. For instance, the intensity of support available at weekends is generally less than that available during the week, which may subsequently affect breastfeeding rates. We have no reason to believe it has a direct effect on outcomes, thus satisfying (2) (a possible concern is with planned Caesarean sections, which we would exclude from the analysis). And because time of delivery is a fairly random event, we believe it satisfies requirement (3).

It is for this reason that we are seeking access to the data already collected by the ALSPAC study. It is an ideal data set to use to address our research questions: on the one hand it has extremely detailed information on pregnancy, labour, delivery and infant-feeding practices; and on the other, very detailed information on child measurement and assessment.

Apart from the information contained in the questionnaires and the child measurements, the methodology also requires access to the variable day of birth.

We anticipate that we could use many of the variables collected under the ALSPAC study. The information collected before birth will be used to check the suitability of the instrumental variable (day of the week should be uncorrelated with background variables). The longer the list of variables that we will present, the more credible our instrumental variable will be. We will also use information on child questionnaires and measurements to build our outcome variables (child's health and development). We will also use parents' information collected after birth to consider the pathways through which breastfeeding could affect the outcomes (for instance, whether parental investments in the child follow compensating or reinforcement behaviours)

At this preliminary stage of the research it is difficult to pin down exactly which variables we would use. Moreover, the results of the estimations will inform us on what other variables to use. For these reasons, ideally we would like to have access to :(1) day of birth, (2) all variables in the child and parents questionnaires collected at any moment in time, (3) assessments (4) linkage with school data, (5) variables that have been derived from biological samples at any moment in time

Date proposal received: 
Thursday, 3 June, 2010
Date proposal approved: 
Thursday, 3 June, 2010
Keywords: 
Diet, Eating Disorder
Primary keyword: 

B1003 - Genome-wide association analysis of pubertal growth - 02/06/2010

B number: 
B1003
Principal applicant name: 
Diana Cousminer (Not used -1, Not used -1)
Co-applicants: 
Elizabeth Widen (Not used 0, Not used 0), Dr Nic Timpson (Not used 0, Not used 0)
Title of project: 
Genome-wide association analysis of pubertal growth
Proposal summary: 

Not available

Date proposal received: 
Wednesday, 2 June, 2010
Date proposal approved: 
Wednesday, 2 June, 2010
Keywords: 
Endocrine, Genetics, Obesity, Weight
Primary keyword: 

B999 - Is locus of control a mediator in the association between early years adversity and depression - 01/06/2010

B number: 
B999
Principal applicant name: 
Dr ?m?r Budanur Miles (University of Bristol, UK)
Co-applicants: 
Prof Ricardo Araya (University of Bristol, UK), Dr Carol Joinson (University of Bristol, UK)
Title of project: 
Is locus of control a mediator in the association between early years adversity and depression?
Proposal summary: 

Objective of the study:This study aims to investigate whether locus of control (LoC) is a mediator in the association between childhood adversity and the development of depression.

The association between childhood adversity and development of depression is well researched and well documented . What we aim to do is to investigate one of the possible mediators or mechanisms of this process, locus of control.

Locus of control is an expression of the style of attribution of responsibility regarding life events and personal experiences. LoC is a trait, in some people, that may develop and change as the the person's psychic maturation progresses. Different types of locus of control has been cited as vulnerability/protective factors in the development of/protection and recovery from internasiling disorders.

In order to study whether locus of control is a mediator in the association between childhood adversity and development of depression, we will investigate a subpopulation of ALSPAC participants who experienced childhood adversity. We will divide this subpopulation into two groups, those who develop depression (depression+) and those who do not (depression-) as well as treating depressive symtpoms as a continuous variable using MFQ scores. Then we will compare these two groups with regard to their locus of control and life events and other forms of adversity. Our hypothesis is that in the presence of adversity the group with an internalised locus of control will show lower levels of depression.

We will initially perform a descriptive statistical analysis of the data obtained. Then we will compare the two groups by using an appropriate regression model taking into account possible confounders and effect modifiers. We will perfom separate analysis by gender to examine whether there are sex differences in the effects.

To perform this analysis we will need information on the participants experience of childhood adversity, diagnosis of depression (DAWBA), depressive symptoms (MFQ), locus of control at different stages during their childhood. To control for confounders and effect modifiers we will need information on sex, IQ, socioeconomic status, maternal depression, maternal locus of control.

Date proposal received: 
Tuesday, 1 June, 2010
Date proposal approved: 
Tuesday, 1 June, 2010
Keywords: 
Depression, Mental Health
Primary keyword: 

B998 - A graphical model approach to pedigree construction using constrained optimisation - 26/05/2010

B number: 
B998
Principal applicant name: 
Dr James Cussens (University of York, UK)
Co-applicants: 
Dr Nuala Sheehan (Not used 0, Not used 0), Prof Paul Burton (Not used 0, Not used 0), Prof George Davey Smith (University of Bristol, UK)
Title of project: 
A graphical model approach to pedigree construction using constrained optimisation
Proposal summary: 

I am currently preparing a grant application for the MRC Methodology panel with a computer scientist from York, James Cussens (PI), to investigate the potential of powerful graph-learning algorithms for reconstructing pedigrees with maximum likelihood from genetic marker data. This is a problem that I have been working on for a few years with a Norwegian collaborator, Thore Egeland, but our emphasis has been very much on forensic identification applications and we have taken a more traditional statistical genetics approach. A pedigree is a special type of graph in that nodes representing individuals can only have two parents and parents must be labelled as being of opposite sex. Consequently, general graph learning algorithms are not very efficient unless they are suitably modified, although we do not have the additional problem encountered in other applications of having to learn the probabilities on the edges (arrows) between nodes as these derive from our knowledge of the genetic model under consideration. James has been in communication with us for some time and has considered a number of approaches to this specialised graph learning problem. He has decided that an approach using constrained optimisation using integer linear programming is the most promising. Indeed, initial results for a simplified situation whereby all individuals are observed and are totally ordered by age are promising, and much faster than competing methods, so we are quite optimistic.

Classical approaches to pedigree reconstruction developed 40 years ago, such as the sequential algorithm of Thompson ? which is a "greedy algorithm", in our terminology ? typically search for "good" but not necessarily optimal pedigrees by starting with sets of individuals that are most likely to be siblings, then finds the most likely parents for these sibships and moves on from there. The resulting reconstruction in heavily dependent on the decisions made about nuclear families at any given stage. Information on the maximal size of a sibship (which will vary across human populations and differ widely from animal and plant populations), the minimal number of years to reach sexual maturity (generation gap), age differences between parents etc. is incorporated in these algorithms at various stages in order to ensure that a realistic structure is produced. These are all "constraints" and one of our first tasks will be to search the statistical literature for those that are known to be important and then find a way to express them as linear constraints. All these algorithms assume complete data which we will typically not have. Searching over all possible pedigrees with missing individuals is much harder and is the interesting problem for the graph learning community. We will begin with a likelihood approach but will then move to a Bayesian framework where ""hard" prior information e.g. on certain known relationships and "soft" prior information e.g. this population is known to favour first cousin marriages etc. can all be incorporated. We will start with simulated data, moving from classic unlinked microsatellite-type data to linked markers and dense sets of SNPs: the likelihood calculations become more problematic then and we will need to employ Markov chain Monte Carlo methods to approximate likelihoods that are intractable with exact methods.

Besides the fact that this is a really nice graph theory problem, the main medical application is the potential for finding sets of related individuals from large Biobank populations for later linkage studies, or for homozygosity mapping where distantly related individuals are better because the shared environmental effects won't mask the relatively small effects of the rarer variants we're trying to find. Identifying the correct pedigree/relationship is crucial for forensic and population wildlife management applications, of course. It is also important for linkage analysis but is overkill for homozygosity mapping where you just need individuals with reasonable IBD-sharing probabilities. However, these general machine-learning algorithms are extremely efficient so if we can tailor-make one for pedigrees that will work quickly, we can obviously get distant relatives easily. We will then need to check sensitivity to getting the right relationship and investigate how best to choose relatives for homozygosity mapping from any constructed extended pedigree.

This is a methodological project with some very hard problems to solve before we get close to using it for anything. There are obviously ethical issues as to when and where you could do this in practice, but for now, we just want to see if it can be done. We will clearly do most of the work with simulated data but we will need a real dataset to check that what we are finding is not totally due to how we simulated. The main application is aimed at UK Biobank which has referred to the desirability of being able to infer relatives at a later point in its protocol. However, as they are a long way off genotyping, we will need a back-up data set to test things on if we get funded and if Biobank takes more than three years to deliver. Other existing cohort studies are probably not large enough to capture any relatives by chance. Obviously there are very close relationships in ALSPAC which are a bit too easy to find but, given that every birth in Avon over a two year period was included, we thought that there might be siblings or even a few cousins there. Our main intention would be to see if we can recover relationships you already know about - not to find hidden ones - although there is a possibility that the ones you know about are not quite as stated. Obviously all ethical issues will have to be handled as deemed appropriate at the time. In particular, we are not interested in any analysis of the ALSPAC data for relatedness, per se, so nothing will be published without clearing everything beforehand. Also, authorship of any paper that uses the ALSPAC data in any way at all, be it for the machine learning, statistical genetics, forensics or medical communities, will include appropriate ALSPAC investigator(s) and this will be discussed with you as beforehand.

Paul Burton (Leicester) and George Davey Smith (Bristol) are both coming on board as full investigators, not because of their great desire to learn about constrained optimisation but because we feel we need their input and experience to ensure a) that the focus of the research stays on medical applications and b) that anything to do with real data will be handled correctly. Knowing them both, I am confident that they will advise us well. I am being deliberately vague about what data we require because we do not know exactly what we need yet, it will be a long time before we need it and much more information than the above will have to be provided then. George mentioned that Illumina quad GWAS data would be available so once we have the machinery in place to handle dense SNP arrays, access to some of that data would be something to discuss. Right now, for the purposes of the grant application, I would like to be able to say, with your permission, that we are in discussion with ALSPAC collaborators for real data which will be used to test the methods in an appropriate way when we finally get to that stage.

Date proposal received: 
Wednesday, 26 May, 2010
Date proposal approved: 
Wednesday, 26 May, 2010
Keywords: 
Genetics
Primary keyword: 

B1001 - EAGLE consortiums Internalizing Behaviour GWAS meta-analysis - 25/05/2010

B number: 
B1001
Principal applicant name: 
Dr Henning Tiemeier (Erasmus University Medical Center, Rottterdam, the Netherlands, Europe)
Co-applicants: 
Fleur Velders (Not used 0, Not used 0), Camilla Stoltenberg (Not used 0, Not used 0), Dr Beate Glaser (Not used 0, Not used 0)
Title of project: 
EAGLE consortium's Internalizing Behaviour GWAS meta-analysis
Proposal summary: 

Concept: Measurement Person Source Time points

Internalizing behaviour SDQ emotional symptoms mother report Questionnaire 4-13yrs.

continuous measurement

SMFQ mother report Questionnaire 10-16yrs.

continuous measurement

EAGLE-WITHIN-COHORT-ANALYSIS-PLAN-Internalizingbehaviour-170310

In this document:

1. Traits of interest

2. Participating studies

3. Number of subjects

4. Genotyping + Imputation

5. Model of association.

6. Data exchange

7. Analysis plan

8. Secondary analysis

9. Proposed deadline

1. Traits of interest

First round: Internalizing behaviour at preschool age (0-7yrs.) continuous measure (int_cont_preschool)

Second round (data added to first round): Internalizing behaviour at school age (8-17yrs.) continuous measure (int_cont_school)

2. Participating studies (as of 10-09-2009)

Fleur Velders, Henning Tiemeier (Generation R),

Joachim Heinrich (LISA)

Beate Glaser, George Davey Smith (Alspac),

Elena Hyponen, Chris Power (1958BC),

Sandra Louis, Lyell Palmer (RAINE),

Pal Suren, Camilla Stoltenberg (MOBA).

3. Projected number of subjects:

4. Genotyping + Imputation

* Genotyped SNPs (Affymetrix, Illumina, Perlegen)

* Imputation HapMap Phase II CEU SNPs. Preferred release 22 of HapMap, build 36. Predefined marker filters to apply before imputation (HWEPgreater than 10-6, MAFgreater than 0.01, SNP-callgreater than 95%). Suggestion left open to cohorts to apply specific filters but should be reported.

* Analyse all SNPs, no filtering on call rate/HWE/MAF/imputation quality (QC metrics to be reported, and filtering will be done at meta-analysis stage)

5. Model of association

* Additive model (SNP coded as allele dose from 0 to 2), which accounts for genotype imputation uncertainty by use of linear regression onto estimated dose (as included in MACHQTL, ProbABEL, SNPTEST), adjusting for population structure and covariates.

6. Data exchange

* See separate RESULTS_FORMAT file for details of results file formatting and file naming.

* Summary statistics to be uploaded to the AIMS system (available?) (link will be provided)

* Only summary statistics will be transferred, not individual level genotype or phenotype data.

7. Analysis outline

* First round: int_cont_preschool

* Second reound: int_cont_school all items:

Internalizing behaviour:

CBCL: broad band scale internalizing problems

SDQ: subscales internalizing behaviour

Rutter: subscales internalizing behaviour

* how to deal with missings? Suggestions:

o allow 25% mssings per scale

o minimum of 10 items per scale

o cohort specific

* Transformation of outcome variable:

o intbeh Z-score = calculate a Z-score

= standardised score

= [value-mean]/standard deviation

(based on the mean and SD internalizing problems score in the sample)

* Model:

o Z-score = SNP + sex + age

- SNP = child genotype

- Sex: coded 1 for male, 2 for female

- Age: at measurement

* Exclusions:

o One of sibling twins or correction

o Non-Caucasian

8. Secondary analyses (for later discussion)

* Dichotomous measurements

9. Deadline

* The proposed deadline for uploading = end of May 2010.

Date proposal received: 
Tuesday, 25 May, 2010
Date proposal approved: 
Tuesday, 25 May, 2010
Keywords: 
Depression, Genetics, Mental Health
Primary keyword: 

B1000 - Gender-specific genomewide association study for circulating levels of fasting glucose and insulin - 20/05/2010

B number: 
B1000
Principal applicant name: 
Dr Reedik Magi (University of Oxford, UK)
Co-applicants: 
Dr Inga Prokopenko (University of Oxford, UK), Dr Nic Timpson (University of Bristol, UK)
Title of project: 
Gender-specific genomewide association study for circulating levels of fasting glucose and insulin
Proposal summary: 

Not available

Date proposal received: 
Thursday, 20 May, 2010
Date proposal approved: 
Thursday, 20 May, 2010
Keywords: 
Genetics
Primary keyword: 

B994 - Association between SNPs of the IGF Axis against antenatal and postnatal growth - 28/04/2010

B number: 
B994
Principal applicant name: 
Priyakumari Parmar (University of Western Australia, Australia)
Co-applicants: 
Prof Lyle Palmer (Not used 0, Not used 0), Dr Craig Pennell (Not used 0, Not used 0)
Title of project: 
Association between SNPs of the IGF Axis against antenatal and postnatal growth
Proposal summary: 

A manuscript has already been prepared assessing the association between SNPs of the IGF Axis and developmental growth

- 165 SNPs were tagged in Raine as being part of the IGF Axis

- 145 SNPs were used in analyses (20 SNPs were excluded for being inHWE disequilibrium, LD, not genotyped properly less than 80%, and MAF less than 10% in HapMap and Raine)

- Longitudinal analyses for antenatal measures: abdominal circumference, head circumference and ratio of head to abdominal circumference

- Cross-sectional analyses for birth weight, abdominal circumference, head circumference and ponderal index (for measurements taken at birth - on day 2 of life)

- Longitudinal analyses of BMI from year 1 to year 17

- A total of 63 SNPs (out of 145 SNPs) gave at least one significant association (p less than 0.05) with a measure of developmental growth (at birth or antenatal level)

- The following table summarises the analyses

Time

Type of analysis

Outcome

Covariates

Birth

(day 2 of life)

Cross-sectional

Abdominal Circumference

Gestational age, parity, placental weight and maternal diabetes

Head Circumference

Gestational age, parity, placental weight and maternal education

Birth Weight

Gestational age, parity, placental weight

Ponderal Index

Gestational age, placental weight, maternal BMI, maternal and paternal age

Year 1

Cross-sectional

Percentile change in weight

Gestational age, parity, placental function, maternal diabetes and breast-feed

Year 1-18

Longitudinal

BMI

Age

The phenotypic data required for the research in this proposal includes all outcomes and covariates outlined in the table above and are listed below:

  • Data on:
    • Maternal and Paternal age and education
    • Maternal smoking status, BMI, hypertension, diabetes and anemia (during pregnancy)
    • Gestational age
    • Placental weight and function
    • Parity
    • Child breast-feed
    • Gender of child
  • At Birth
      • Abdominal circumference
      • Head circumference
      • Birth weight
      • Ponderal index
  • Postnatal
    • Year One of life
      • Percentile change in weight (since birth)
    • Years One-Eighteen

BMI

Date proposal received: 
Wednesday, 28 April, 2010
Date proposal approved: 
Wednesday, 28 April, 2010
Keywords: 
Genetics
Primary keyword: 

B996 - Testing the combined effects of antenatal and postnatal stressful environments on child development - 23/04/2010

B number: 
B996
Principal applicant name: 
Sara Jaffee (King's College London, UK)
Co-applicants: 
Dr Edward Barker (King's College London, UK)
Title of project: 
Testing the combined effects of antenatal and postnatal stressful environments on child development.
Proposal summary: 

Background: A number of studies have shown that maternal stress during pregnancy has effects on

offspring behaviour independent of postnatal measures of maternal stress. However, animal studies have

shown that behavioural development is influenced by the interaction of antenatal and postnatal

environments (Francis et al. 2003). Data are needed to test the co-action of antenatal and post-natal

environments in humans.

Aims: The proposed research has two aims: (1) to identify trajectories of familial risk from the prenatal to

the postnatal period, (2) to 'test whether familial risk trajectories up to age 8 years are associated with

child cognitive abilities and behaviour from 8 to 10 years. The design will provide evidence as to the

relative importance of antenatal versus postnatal environments and test additive versus interactive models

of antenatal and postnatal effects.

Hypothesis 1: We will identify trajectories that reflect (a) consistently low levels of familial risk, (b)

increasing risk from the antenatal to postnatal period, (c) decreasing risk from the antenatal to postnatal

period, (d) stable and high levels of familial risk.

Hypothesis 2a: If antenatal environments have enduring effects irrespective of postnatal environments,

children on the stable, high risk and declining trajectories will have poorer outcomes than children on the

stable, low risk and increasing risk trajectories.

Hypothesis 2b: If postnatal environments have effects on child outcome irrespective of antenatal

environments, then children on the stable, high risk and increasing risk trajectories will have poorer

outcomes than children on the stable, low risk and declining risk trajectories.

Hypothesis 2c: If antenatal and postnatal environments have additive effects, then children on the stable,

high risk trajectory will have the poorest outcomes, children on the stable, low risk trajectory will have

the most positive outcomes, and children on the increasing and declining trajectories will fall intermediate

to the other two groups.

Hypothesis 2d: If antenatal and postnatal environments have interactive effects, then children on the

stable, high risk trajectory will have poorer outcomes than the other three groups.

Analysis: The analysis would involve Cl) estimating trajectories of environmental risk from the antenatal

through the postnatal period up to age 8 years involving a composite index of financial hardship,

domestic violence (as reflected in mothers' reports of conflict with partner and in life events

questionnaire), child harm (as reflected in life events questionnaire), maternal social support, and

maternal depression and anxiety; (2) estimating associations between environmental risk trajectories and

child behaviour (symptoms of antisocial behaviour, depression, and attention deficit/hyperactivity) and

cognitive outcomes (IQ) at 8 to 10 years. Analyses would control for antenatal smoking and alcohol use

as well as parent education and parental history of antisocial behaviour and mental health problems.

Date proposal received: 
Friday, 23 April, 2010
Date proposal approved: 
Friday, 23 April, 2010
Keywords: 
ADHD, Behavioural Problems, Depression
Primary keyword: 

B987 - Facial landmark data and ocular measures in the ALSPAC cohort - 21/04/2010

B number: 
B987
Principal applicant name: 
Dr Jay Self (Not used 0, Not used 0)
Co-applicants: 
Prof Stephen Richmond (Not used 0, Not used 0), Alexei Zhurov (Not used 0, Not used 0), Arshed Toma (Not used 0, Not used 0), Ms Cathy Williams (Not used 0, Not used 0), Dr Kate Northstone (Not used 0, Not used 0)
Title of project: 
Facial landmark data and ocular measures in the ALSPAC cohort
Proposal summary: 

Draft proposal of Initial analyses of available data

Introduction and background

From the development of the bony orbit through to the complex interconnection of neuronal circuitry required for stereoscopic vision, the factors controlling growth and development of the visual system in humans are poorly understood. In such a sensitive and plastic system, developmental anomalies are extremely common. In many circumstances small but timely interventions can result in significant improvements in vision which serve that individual for life.

Strabismus (squint) describes misalignment of the visual axis of one eye with respect to the other. It is thought to affect between 2 and 4% of the population and in most cases results in loss of vision and/or loss of stereoscopic vision1. Some squints are convergent and some divergent. In some cases it is not clear why the eye is divergent rather than convergent or visa-versa. Convergence is closely related to many forms of convergent squint as is the refractive condition of the developing eye2. Similarly, the distance between the eyes in the horizontal plane is known to alter the amount of convergence required for binocular vision and the degree of stereopsis in the general population can vary greatly. Therefore, it is possible that by altering the requirement for convergence, the physical distance between the eyes in the horizontal plane is a risk factor for squint and for varying grades of stereoscopic vision.

The factors influencing the growth of the bony orbit and its relationship to development of the globe are also poorly understood. However, it is known that extreme anomalies of globe growth can result in significant growth changes in the developing orbit. For example, in infants with either absent (anophthalmos) or very small globes (microphthalmos) the orbit is known to under-develop such that tissue expanders are sometimes used to treat asymmetry. Conversely, for infants with marked enlargement of the globe (Buphthalmos) which is often related to congenital glaucoma, the bony orbit is enlarged3.

It is therefore evident that extreme variations in the growth of the globe can influence the growth of the bony orbit and resulting facial character. Perhaps more subtle variations in globe size also have an effect on the development of the bony orbit.

Proposed study

ALSPAC is an ongoing population-based birth cohort into which over 14,000 mothers-to-be were recruited in the Southwest of England (http://www.bristol.ac.uk/alspac/). Approximately 11-12,000 children and their families are still participating and the "children" are now on the verge of adulthood (17 - 19 years). ALSPAC has assembled detailed exposure and developmental data on these children and their families in addition to genetic information leading to the production of numerous peer reviewed publications in prestigious journals4.

Data relevant to this proposed study include 3D facial scans for 4200 individuals of the ALSPAC cohort when aged 15, processed and landmarked by Professor Richmond's group in Cardiff. The 3D facial scans were captured using 2 high resolution Konica/Minolta laser scanners. These scans provide exquisite detail of the surface characteristics of each participants face and allow measurement of facial features and comparison with age matched controls to an accuracy of 0.3mm. These data have been 'landmarked' over various periocular structures to allow measurements of anatomical structures such as inter-canthal distance and new landmarks can be created for each scan to measure an infinite number of facial characteristics.

Further relevant data includes assessments of ocular biometry, alignment and stereoscopic vision measurements for the same 4200 children with facial scans, collected at ages 7 - 15 years, thus providing a uniquely detailed dataset of ocular development and facial characteristics in a large sample of children.

We will investigate the hypothesis that mild to moderate variations in globe size alter the growth of periocular structures. From those ALSPAC children with 3D facial scans and ocular biometry for each eye collected at age 15 (n = 2837), approximately 5% (134) have an interocular difference in axial length of 0.5 mm or greater. We will obtain a Left vs Right asymmetry measurement (as in figure 1) for the periocular landmark data and compare the asymmetry of the two groups and therefore the degree of facial asymmetry with the degree of ocular size asymmetry.

Additionally, we will compare the same periocular landmarked data in children (obtained at age 15) with orthoptic measurements obtained at age 7 years (strabismus) or stereoscopic vision (obtained at 7, 11 and 12 years), to investigate the relationship between horizontal distance between the visual axes and the incidence of squint and reduced levels of stereopsis (depth perception). We anticipate that the majority of children with 3D face data will have been examined at age 7: of these approximately 3.5% (estimated n = 140) will have had a strabismus at that age and are highly likely still to be strabismic at 15 as the condition does not spontaneously resolve and even surgery rarely removes all misalignment. We will investigate the hypothesis that the occurrence of ocular misalignments (manifest squints) is modified by the distance between the ocular axes, for example that the risk of convergent strabismus increases as the horizontal distance between the eyes decreases and conversely that the risk of divergent strabismus increases as the eyes are displaced further apart. Stereopsis has been tested at 7, 11 and 12 years and we anticipate that the majority of children with 3D facial data at 15 will have had their stereopsis tested at 7 years, and again at 11 years. We will investigate the hypothesis that, in children with no strabismus, the accuracy of depth perception is related to the horizontal distance between the eyes.

We will perform a variety of statistical analyses looking for associations between these parameters and ocular landmark measurements. The details of the individual tests will be clarified when feasibility and numbers for each individual dataset are ascertained. We anticipate using univariate and subsequently multivariate analyses using appropriate covariates including sex etc. Dr Kate Northstone will act as "data buddy" as part of her funded programme of work with CW and will advise on analytic approaches as needed. Data transfer will take place using a specific procedure designed to collaborate with Prof Richminds group, who unusually have the alspac clinicID as the identifier on the face-shape data they acquired. Thus KN will send Prof Richmond the clinicIDs of all participants for whom we have the specified vision variables; Prof R will then send KN the derived face landmark variables; KN will attach to this file the vision data and will remove clinicID and replace it with a collaborator ID. This stand-alone file can then be analysed in Cardiff or Southampton as appropriate.

Additional statistical support will be sought where necessary from Dr Sarah Ennis from the Bioinformatic Unit at Southampton General Hospital, and Professor Clive Osmond, Professor of medical statistics at Southampton's MRC Epidemiology resource centre

We anticipate acquiring sufficient numbers to investigate the associations of various ocular parameters with periocular facial landmarks. This will provide some exiting information about the complex interaction between physical ocular anatomy, visual development and the interaction of orbital and ocular growth. This could provide some interesting epidemiological data in addition to a greater understanding of visual system development. It is anticipated that this work will lead to the publication of research papers in peer reviewed journals and may provide preliminary data for further work in this cohort perhaps using genetic data.

Date proposal received: 
Wednesday, 21 April, 2010
Date proposal approved: 
Wednesday, 21 April, 2010
Keywords: 
Development, Neurology, Vision
Primary keyword: 

B986 - Facial landmark data ocular development and maternal alcohol consumption in the ALSPAC cohort - 21/04/2010

B number: 
B986
Principal applicant name: 
Dr Jay Self (University of Southampton, UK)
Co-applicants: 
Prof Stephen Richmond (Not used 0, Not used 0), Miss Cathy E M Williams (Not used 0, Not used 0), Dr Marko Kantomaa (Not used 0, Not used 0), Arshed Toma (Not used 0, Not used 0), Alexei Zhurov (Not used 0, Not used 0), (University of Bristol, UK)
Title of project: 
Facial landmark data, ocular development and maternal alcohol consumption in the ALSPAC cohort
Proposal summary: 

We wish to identify those ALSPAC children who have had 3D facial scans, orthoptic assessments, refraction, clinical examination and for whom we have maternal alcohol intake data. We will stratify alcohol exposure as done previously for this cohort into women who drank no alcohol in pregnancy, or less than 1 drink per week, or more than on drink per week (2). In this earlier ALSPCAC paper, effects on child temperament were identified after exposure to greater than 1 drink per week during pregnancy (approx 16% women in that analysis), suggesting there is enough variation in alcohol exposure within the cohort for useful analyses of outcome. We will perform a variety of statistical analyses seeking to examine associations between alcohol exposure and facial anatomical and ophthalmic measurements. For example, category of first trimester alcohol intake as a predictor or modifier of (a) palpebral aperture width (between medial and lateral canthi), (b) distance between the eyes (between the medial canthi) (c) occurrence, direction and magnitude of strabismus (assessed at age 7) and refractive error (outcome data at age 3 for 2000 and at age 15 for approx 5000) and ocular biometry (available for 2900 at age 15).

Date proposal received: 
Wednesday, 21 April, 2010
Date proposal approved: 
Wednesday, 21 April, 2010
Keywords: 
Alcohol, Drugs, Smoking
Primary keyword: 

B991 - Acoustic markers to recover the phenotype in residual speech errors A feasibility study - 18/04/2010

B number: 
B991
Principal applicant name: 
Yvonne Wren (North Bristol NHS Trust, Bristol)
Co-applicants: 
Prof Lawrence Shriberg (University of Wisconsin-Madison, USA)
Title of project: 
Acoustic markers to recover the phenotype in residual speech errors: A feasibility study.
Proposal summary: 

Not available

Date proposal received: 
Sunday, 18 April, 2010
Date proposal approved: 
Sunday, 18 April, 2010
Keywords: 
Speech & Language
Primary keyword: 

B990 - Epigenetic Pathways to Conduct Problem Trajectories the Role of Prenatal and Postnatal Environmental Risk Exposures - 18/04/2010

B number: 
B990
Principal applicant name: 
Dr Edward D Barker (University of Alabama, USA)
Co-applicants: 
Dr Jonathan Mill (Not used 0, Not used 0), Prof Barbara Maughan (Not used 0, Not used 0), Prof George Davey Smith (Not used 0, Not used 0), Dr Caroline Relton (Not used 0, Not used 0), Dr Beate Glaser (Not used 0, Not used 0), Dr Susan Ring (Not used 0, Not used 0)
Title of project: 
Epigenetic Pathways to Conduct Problem Trajectories: the Role of Prenatal and Postnatal Environmental Risk Exposures
Proposal summary: 

AIMS

Specific Aim 1: Longitudinal methylomic analyses in each trajectory group

o Perform a hypothesis-free genome-wide screen of DNA methylation in the 200 individuals using the Illumina Infinium 27K Methylation array on bisulfite-treated DNA from samples obtained at birth, age 7 and age 15

o Perform extended fine-mapping verification analyses across specific genomic regions nominated from the microarray screen using Pyrosequening and/or the Sequenom EpiTYPER system in larger numbers of cases and controls.

o Assess the extent to which dynamic patterns of methylation vary across the trajectories

o Is there variation in the epigenetic-regulation of genes in the trajectories relative to controls?

? We would estimate "methylation trajectories" conditional on the conduct trajectories in an attempt to sort "noise" from the potentially informative changes in gene regulation

Specific Aim 2: Examine candidate-gene DNA methylation patterns

o Focus on HPA axis regulatory genes known to functionally inter-relate with serotonin

o e.g., corticotropin-releasing hormone (CRH), CRH receptors, CRH binding proteins, pro-opiomelanocortin (POMC), steroid hormone biosynthetic enzymes, etc.).

o Focus on testosterone (androgen) receptors, androgen biosynthesis pathways, monoamine/catecholamine-related genes (e.g., monoamine oxidase, transporters)

o Quantitative analysis of DNA methylation across gene promoter regions using using Pyrosequening and/or the Sequenom EpiTYPER system .

o Perform extended fine-mapping verification analyses across specific genomic regions nominated from the microarray screen using Pyrosequening and/or the Sequenom EpiTYPER system in cases and controls.

o Assess the extent to which dynamic patterns of methylation vary across the trajectories

o Is there variation in the epigenetic regulation of genes in the trajectories relative to controls?

We would estimate "methylation trajectories" conditional on the conduct trajectories in an attempt to sort "noise" from the potentially informative changes in regulation

Specific Aim 3: examine associations between DNA methylation trajectories and environmental

risk exposures from gestation though to adolescence

3.1 Data collection.

DNA from samples obtained at birth, age 7 and age 15

3.2 Existing Data Required

Environmental risk data are listed in the previous section. The genes we propose to genotype for the candidate methylation scans are listed in the next section.

3.4 Data Analysis.

See specific aims (above). Epigentic analysis will take place at the The Institute of Psychiatry Psychiatric Epigenetics Group, King's College London.

Date proposal received: 
Sunday, 18 April, 2010
Date proposal approved: 
Sunday, 18 April, 2010
Keywords: 
ADHD, Behavioural Problems, Genetics, Epigenetics , Environmental Exposure
Primary keyword: 

B985 - A genome-wide study of CNVs gene expression and quantitative traits in the ALSPAC population cohort - 15/04/2010

B number: 
B985
Principal applicant name: 
Dr Panos Deloukas (Wellcome Trust Sanger Institute, London, UK)
Co-applicants: 
Prof Emmanouil Manolis Dermitzakis (University of Geneva Medical School, Switzerland, Europe), dR Matthew Hurles (Wellcome Trust Sanger Institute, London, UK), Dr Nigel Carter (Wellcome Trust Sanger Institute, London, UK)
Title of project: 
A genome-wide study of CNVs, gene expression and quantitative traits in the ALSPAC population cohort
Proposal summary: 

Summary and timescale

As part of an established colaboration between the University of Bristol and the Sanger Institute we have collected whole genome data on gene expression, SNP and copy number variation in 1,000 individuals belonging to the ALSPAC population cohort. We propose to use these data sets to study the relationships between genetic variation, gene expression regulation and complex traits.

We seek permission to obtain the three data sets generated throught the ALSPAC - Sanger Institutte collaboration from the 1,000 densely-phenotyped individuals namely

- intensity data of the CNV array used to profile the above individuals

- intensity data of the 48,000 transcripts assayed using the Illumina Expression BeadChip platform. The data will be normalised and gene expression levels will be determinrd as part of the down stream analyses.

- genotypes of the 317K or 660K SNP arrays

We will associate gene expression data against CNVs and SNPs to identify genetic variants that influence gene regulation in both cis and trans, and characterise the nature of these associations. We will further associate these data sets with the 20 primary phenotypes outlined in Table 1 with

(i) expression levels of 48,000 transcripts

(ii) SNPs and CNVs

We would like to request at this stage

Sex Child

Body weight Child Clinic latest age

Height Child '' latest age

Expression array data (intensities) Child

Genotype data (317K or 660K array) Child

CNV array data (intensities)

Date proposal received: 
Thursday, 15 April, 2010
Date proposal approved: 
Thursday, 15 April, 2010
Keywords: 
Genetics
Primary keyword: 

B984 - Prevalence and risk factors of hyperacusis in children at age 11 years - 12/04/2010

B number: 
B984
Principal applicant name: 
Dr Amanda J Hall (University of Bristol, UK)
Co-applicants: 
Dr Melanie Parker (Not used 0, Not used 0)
Title of project: 
Prevalence and risk factors of hyperacusis in children at age 11 years
Proposal summary: 

Background:

Hyperacusis is defined as oversensitivity to some everyday sounds (lowered threshold of discomfort to sounds). Children may complain that their ears hurt when exposed to some sounds, typically high pitched or unexpected loud noises. For some children, this can be extremely distressing and can have a significant effect on behaviour. Phonophobia is defined as a fear of sound and in the most extreme cases, the lowest level of the particular sound can trigger what appears to be a disproportionate reaction, with physical symptoms of anxiety, tantrums and avoidant behaviour.

Certain groups of patients are known to be at greater risk of experiencing hyperacusis. It is a common and often disabling condition in Williams Syndrome and has been associated with abnormal cochlear function (Gothelf et al, 2006). It is the commonest sensory perceptual abnormality in children who are on the Autistic Spectrum, with prevalence ranging from 15-100% (Gomes et al, 2008). In these children there is little evidence of peripheral audiological abnormality (Gravel et al, 2006). Research has shown that there are more likely to be central causes for the unusual reactions to auditory stimuli in these children (Khalfa et al, 2001; Orekhova et al, 2008; Jones et al, 2009).

A recent study of 506 children between the ages of 5 and 12 years has used a questionnaire to assess the prevalence of hyperacusis in typically developing children (Coelho et al, 2007a). This identified that hyperacusis was reported by 3.2% of children. The same population was also asked questions related to tinnitus (Coelho et al, 2007b). 37% of children reported hearing a noise inside their head and 17% described it as annoying. Risk factors for experiencing tinnitus included young age, hearing loss and hyperacusis.

The ALSPAC data offers a unique opportunity to establish the prevalence of hyperacusis in a large population of children and to evaluate whether there are any significant associations with early life history, including detailed hearing data.

Research aims and objectives:

1. To determine the prevalence of hyperacusis in the ALSPAC cohort at age 11 years

2. To investigate risk factors for hyperacusis, specifically to examine:

a) Child factors: gender, prematurity, birthweight, migraine, special educational needs (ASD, ADHD & other conditions), meningitis & encephalitis, head injury requiring hospitalisation

b) Auditory function: hearing and acoustic reflex thresholds, current and historical otitis media with effusion, tinnitus

c) Socioeconomic factors: socioeconomic status, maternal education and housing tenure

Methods:

At the age 11 Focus clinic, approximately 7000 children were asked about sensitivity to sound, known as hyperacusis. Pilot analysis showed that approximately 3 % of these children reported hyperacusis of which 60% had experienced it for at least a year. Children were also asked whether they experienced noises in their ears (tinnitus) and pilot analysis showed that children with hyperacusis were more likely to report tinnitus than children without hyperacusis.

We intend to explore the characteristics of children reporting hyperacusis to determine possible risk factors for this condition. We will use univariate and multivariate logistic regression to determine whether those with hyperacusis have common factors in their early medical history (see objective 2a). We will also determine whether there are any differences in pure tone and acoustic reflex thresholds. Finally, we will examine socioeconomic factors.

Date proposal received: 
Monday, 12 April, 2010
Date proposal approved: 
Monday, 12 April, 2010
Keywords: 
Hearing
Primary keyword: 

B997 - Childhood health and facial markers of developmental instability - 07/04/2010

B number: 
B997
Principal applicant name: 
Mr David Lawson (London School of Hygiene and Tropical Medicine, UK)
Co-applicants: 
Prof Ian Penton-Voak (Not used 0, Not used 0), Nicholas Pound (Brunel University of London, uk), Prof Stephen Richmond (University of Cardiff, UK), Arshed Toma (University of Cardiff, UK)
Title of project: 
Childhood health and facial markers of developmental instability
Proposal summary: 

CHILDHOOD HEALTH AND FACIAL MARKERS OF DEVELOPMENTAL INSTABILITY

Summary:

Facial scan data on the ALSPAC cohort has been collected by Prof Richmond and his team at Cardiff University. We seek permission to analyse this data to produce hypothesised markers of development instability (e.g. facial symmetry, see below) and to link this data with childood health data already obtained by Dr Lawson under an existing project (Project B number: B227 - e,g, Lawson and Mace 2008, 2009).

Background:

Small random deviations from perfect symmetry in normally bilateral traits are referred to as fluctuating asymmetry (FA). Low levels of FA are believed to be an indicator of developmental stability (Van Valen, 1962) ? an organism's ability to buffer against stressors such as pathogens, toxins, and mutations (Moller & Swaddle, 1997; Polak, 2003). Across taxa higher FA is associated with greater morbidity, reduced fecundity, and higher mortality and in humans symmetry is associated with attractiveness. For example, bodily FA is negatively associated with face (Gangestad, Thornhill & Yeo, 1994), voice (Hughes, Harrison & Gallup, 2002), and odour attractiveness (Thornhill & Gangestad, 1999).

Although considerable research effort has addressed the consequences of both bodily and facial symmetry on various outcomes (such as intelligence, personality and attractiveness; Penton-Voak et al, 2001; Pound et al, 2007), the basic assumption of this work -effectively, that symmetry reflects good developmental health - remains untested formally. The ALSPAC sample provides both health data and facial scans from which symmetry measures can be obtained, allowing a rigourous test of this relationship between health and asymmetry.

Hypotheses to be tested:

By investigating the associations between a putative marker of developmental instability (facial asymmetry determined from the 3D facial scans using a landmark based morphometric technique ) and childhood health indices (from Dr. Lawson's previous work), we aim to test the hypothesis that asymmetry results from challenges to health during development

Date proposal received: 
Wednesday, 7 April, 2010
Date proposal approved: 
Wednesday, 7 April, 2010
Keywords: 
Depression, Mental Health
Primary keyword: 

B976 - Understanding the pathways between childhood adversity and psychosis-like symptoms in adolescence - 04/04/2010

B number: 
B976
Principal applicant name: 
Dr Helen Fisher (King's College London, UK)
Co-applicants: 
Prof Dieter Wolke (University of Warwick, UK), Andrea Schreier (University of Warwick, UK), Prof Marcus Munafo (Not used 0, Not used 0), Dr Stanley Zammit (University of Bristol, UK), Prof Glyn Lewis (Not used 0, Not used 0), Prof Barbara Maughan (King's College London, UK), Dr Peter McGuffin (King's College London, UK)
Title of project: 
Understanding the pathways between childhood adversity and psychosis-like symptoms in adolescence
Proposal summary: 

Aim: To explore whether psychological and psychopathological factors mediate the association between childhood adversity and psychosis-like symptoms in adolescence.

Background:

An increasing body of research has demonstrated an association between adverse childhood experiences and psychotic disorders (e.g., Bebbington et al., 2004; Fisher et al., 2010; Janssen et al., 2004; Shevlin et al., 2007a). As psychosis is considered to be a quantitative continuum from normality through attenuated psychotic symptoms to full clinical disorder (Chapman & Chapman, 1980; van Os et al., 1999), an underlying aetiological continuum is also assumed to exist (Johns & van Os, 2001; Myin-Germeys et al., 2003). Indeed, childhood adversity has also been linked to sub-clinical expressions of psychosis (e.g., Freeman & Fowler, 2009; Gracie et al., 2007; Lataster et al., 2006; Morgan et al., 2009; Nishida et al., 2008; Shevlin et al., 2007b; Thompson et al., 2009), including amongst the ALSPAC cohort (Schreier et al., 2009). These findings suggest that investigating samples with psychosis-like symptoms (PLIKS) may provide useful insights into clinical psychosis. However, little is known about the mechanisms underlying the adversity - psychosis association.

DIRECT: Traumatic events in childhood could directly increase the risk of developing PLIKS, perceptual aberrations or reality impairment (Allen et al., 1997; Honig et al., 1998). Indeed, genetic studies have demonstrated a role for environmental factors in psychosis proneness (Linney et al., 2003), and Cougnard et al. (2007) found that childhood abuse was associated with the initial appearance of PLIKS. These sub-clinical hallucinations or delusions could be considered to be traumatic reactions to severe adversity whose content is directly reminiscent of the adversity (Read et al., 2005). Such direct connections have been reported in between 3% - 50% of individuals studied (Gracie et al., 2007; Hardy et al., 2005; Read & Argyle, 1999). Therefore, a direct pathway between childhood adversity and PLIKS may be operating but perhaps only for a small minority of individuals.

INDIRECT: A range of indirect pathways have been suggested, including psychological mechanisms (low self-esteem, external locus of control, insecure attachment style) and the development of other mental health problems (depression, anxiety, PTSD). For instance, Gracie et al. (2007) showed that negative perceptions of the self and others partially mediated associations between lifetime trauma and PLIKS in a general population sample, but contradictory results were reported by Freeman and Fowler (2009). Insecure attachment styles are also prevalent amongst individuals who have experienced childhood abuse (Alexander et al., 1998) and patients with psychotic disorders (Dozier et al., 1991), especially those with a history of abuse (Tait et al., 2004), suggesting another possible indirect pathway. Furthermore, some studies have reported that the association between childhood abuse and psychosis is attenuated if depression is included as a confounder (Bebbington et al., 2004; Shevlin et al., 2007a), whilst Freeman and Fowler (2009) recently reported that anxiety mediated the association with paranoid delusions amongst abused individuals. Psychotic symptoms have also been hypothesised to emerge after the experience of post-traumatic stress disorder in those exposed to childhood adversity (PTSD; Braakman et al., 2009; Pepper & Agius, 2009). A range of other potential mechanisms may also be operating (e.g., stunted brain development, substance misuse, epigentic changes, gene x environment interactions, dysregulation of the HPA axis, hostile attributions, etc.) but these are beyond the scope of the proposed analysis.

Therefore, further exploration of the pathway(s) between childhood adversity and psychosis is required to test these different mechanisms. Moreover, the handful of studies that have explored this issue to date (e.g., Fowler & Freeman, 2009; Gracie et al., 2007; Whitfield et al., 2005) have all relied on cross-sectional samples, thus preventing temporal relationships from being accurately established.

Hypotheses:

(i) reported exposure to individual and multiple childhood adversities (peer victimisation, sexual abuse, domestic violence, physical abuse, parental loss, emotional abuse, harsh discipline and neglect) will be associated with separation anxiety, low self-esteem, an external locus of control, and higher levels of depression, anxiety and PTSD symptoms;

(ii) in turn these factors will predict greater endorsement of PLIKS at ~13 years; and

(iii) both psychological and psychopathological factors will explain a significant proportion of the variance in the pathway between the adverse childhood experiences and PLIKS with a direct pathway accounting for only a small proportion of the variance.

Analysis:

Single variables for each form of adversity will be constructed based on the presence of that adversity at any of the time points assessments were conducted versus absence across all time points. The mediation of the childhood adversity - PLIKS association by psychological and psychopathological factors will be investigated using a structural equation modelling framework in Mplus. The major advantage of this approach over path analysis is that measurement error arising from repeated assessments of the variables and missing data can be dealt with directly. Specifically two models will tested for each form of childhood adversity:

(i) full mediation of the relationship between childhood adversity and presence of suspected or definite PLIKS by separation anxiety, self-esteem, locus of control, depression, anxiety and PTSD symptoms; and

(ii) partial mediation such that a direct pathway from adversity to PLIKS is also present.

The weighted least-squares estimator will be used to analyse the models as some of the variables are likely to be non-normally distributed and it is robust to data missing at random. The two models will be compared using a chi-square test to determine whether including the direct pathway substantially improves the fully mediated model. The proportion of the variance accounted for by the direct and indirect pathways will also be reported to assess the degree of prediction. Potential confounders (age, gender, ethnicity, social class, IQ, family history of schizophrenia or depression and general family adversity) will be controlled for in the analysis.

Date proposal received: 
Sunday, 4 April, 2010
Date proposal approved: 
Sunday, 4 April, 2010
Keywords: 
Depression
Primary keyword: 

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