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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B626 - Obesity and Lower Extremity Pain in Adolescents - 07/03/2008

B number: 
B626
Principal applicant name: 
Dr Sharon Bout-Tabaku (Children's Hospital of Philadelphia, USA)
Co-applicants: 
Dr Nicolas Stettler (Not used 0, Not used 0), Dr Renee Moore (Not used 0, Not used 0)
Title of project: 
Obesity and Lower Extremity Pain in Adolescents
Proposal summary: 

Pediatric obesity has increased at an alarming rate in the last 30 years. As a result pediatric cardiovascular, endocrine and pulmonary obesity related morbidities have also risen. However, other pediatric complications of obesity important to public health and quality of life, such as bone, joint and muscle pains, are understudied and their prevalence, incidence and etiology remain unclear. In adults there is abundant evidence that obesity is a risk factor in the occurrence and progression of knee pain and knee osteoarthritis (KOA). In children, despite anecdotal and clinical impression there is sparse evidence on the link between obesity and musculoskeletal pain. Once this is understood the association between childhood obesity and its consequences for osteoarthritis can be investigated.

We will characterize the relationship of obesity to lower extremity (LE) pain in adolescents with the following aims:

A. Specific Aims

Specific Aim 1: To estimate the prevalence of LE pain cross-sectionally in all children aged 11-13 and specifically, compare the prevalence of obese adolescents to non -obese adolescents aged 11-13 years.

Hypothesis: Obese adolescents will have LE pain that is double that of their non-obese counterparts in an adjusted analysis.

Specific Aim 2: To estimate, using a cohort study design (in a subgroup with no pain at baseline), the incidence of LE pain among obese compared to non-obese adolescents over a period of 2 years (11 to 13 years).

Hypothesis: In looking at the subgroup with no pain at baseline, the incidence of LE pain will be 2 fold greater in the obese adolescents compared to the non-obese adolescents over these two years.

Secondary Aims:

Our secondary aims will examine other important relationships within the cohort.

To estimate the correlation and trend in the incidence of knee pain among adolescents at increasing levels of obesity.

To explore the effect of lean mass and fat mass in obese adolescents who develop knee pain at year 2.

To understand the effect of activity levels on the association between BMI and LE pain in all subjects at year 2.

To assess the impact of knee pain and obesity on functionality and quality of life.

B. Background and Significance

Childhood Obesity and the Musculoskeletal System

The prevalence of childhood obesity, defined as body mass index (BMI: weight/height2) at or above the 95th percentile of a reference population, has more than tripled in the United States since the 1970's to over 15%. Obesity leads to morbidities in children and is a risk factor for adult morbidity and mortality. Medical problems range from compromised cardiovascular, endocrine and pulmonary health. However, other pediatric complications of obesity important to public health or quality of life, such as bone, joint and muscle pains, are understudied and their prevalence, nature, and consequences unclear.

Certain musculoskeletal disorders such as Slipped Capital Femoral Epiphyses and Blount's disease are clearly linked to excessive weight but the association of obesity on non-specific lower extremity pain is unknown. Pediatric musculoskeletal (MSK) pain constitutes the third leading category for office visits among adolescents and prevalence estimates range from 6-33%, with the leading cause being trauma, followed by mechanical / overuse syndromes. In healthy Spanish children 10% of adolescents presented to doctors offices with MSK pain.In all children knee pain, soft tissue pain and other joint pains represented 65% of all complaints with adolescents localizing pain to the lower limb and lower back. [deInnocencio 2004]

The literature in obese children is sparse however two recent studies found the lower extremities to be the most common site of MSK pain in overweight adolescents compared to controls. A small Brazilian non-population based study demonstrated that obese adolescents had a two fold increase in pain compared to the normal weight counterparts. (sa Pinto 2006)

As the key structural elements for joint health rapidly evolve in healthy adolescents it may be adversely affected by obesity, through unsustainable levels of mechanical loading, which in the short term, may lead to pain and functional disability and in the long term, may irreversibly alter the lower extremity joint milieu.

C. RESEARCH DESIGN AND METHODS

C.1. Choice of Study Design

Until now, existing prevalence data on musculoskeletal pain has a wide range, has not been examined in a large population and has not looked at the impact of obesity. Thus our cross-sectional study design will estimate the prevalence of lower extremity pain in adolescents. Additionally, a longitudinal design using prospective data to estimate incidence has the advantage of assessing directionality and establish causality in the association of obesity on lower extremity pain at baseline (11 yrs) and at follow up (13 years).

C.2. Data source and study subjects

We propose to study subjects from the Avon Longitudinal Study of Parents and Children (ALSPAC) which is a large prospective birth cohort study investigating the health and development of children.

This cohort study is ongoing and starting at the age of 7 had annual assessments performed. Currently 6000 still attend clinic visits and data is being collected on the following variables of interest: age, gender, race, socioeconomic status, parental reports of pain, function and quality of life, height/weight, DXA, medical history and activity.

Inclusion criteria:

The entire ALSPAC cohort of ages 11-13 years will be included for study.

Exclusion criteria:

Subjects with underlying orthopedic conditions, surgery related to the lower extremities, juvenile idiopathic arthritis, other inflammatory lower extremity disorders and those with congenital abnormalities of the lower extremities will be excluded.

C.3. Data to be used:

We propose to use the existing data from the ALSPAC study in all children with visits at age 11 and 13 that include the following variables of interest:

Lower extremity pain is assessed by 2 questions on a validated questionnaire answered by the child and caregiver, as "yes" or "no" format with a followup one speculating on the cause.

Functionality and quality of life(QOL) will be assessed by questionnaire and QOL measures.

Anthropometric data from annual clinic visits include height and weight data. From that the BMI (body mass index) will be calculated using the formula weight/height2 as well as age- and gender-specific standard deviation scores (z scores) for weight, height, and body mass index , using the International Obesity Task Force (IOTF) definitions.

With DXA data we will assess lean and fat mass. Actigraph data will quantify activity levels. Socio-demographic data on socioeconomic status, age, gender and race will be analyzed. Finally, underlying medical history data from the clinic chart will be used to identify subjects for exclusion

D. HUMAN SUBJECTS RESEARCH

D.1. Protection of Human Subjects

a. Risks to the subjects: This protocol incurs minimal risk to the subjects as it uses an existing database with completed data. There will be no interaction with the subjects and no additional data is to be collected on behalf of this protocol.

b. Sources of materials: The data have already been obtained and are being requested to be shared with this investigator under the ALSPAC collaboration agreement. All the variables of interest will be shared as de-identified data.

c. Potential risks and benefits: There are no risks or benefits to the subjects under study. The results of the study will not be shared with the subjects and will not benefit them individually, although results will benefit public health policy initiatives.

D.2. Importance of the knowledge to be gained: The results of this study will provide prevalence and incidence of pain of lower extremties in obese children and reveal the short and long term impact of obesity on the musculoskeletal system with ramifications for further studies.

Date proposal received: 
Friday, 7 March, 2008
Date proposal approved: 
Friday, 7 March, 2008
Keywords: 
Endocrine, Obesity, Weight
Primary keyword: 

B623 - Examination of the relationship between SNPs in genes encoding insulin signalling proteins and insulin resistance - 03/03/2008

B number: 
B623
Principal applicant name: 
Prof Jeremy M Tavare (Not used 0, Not used 0)
Co-applicants: 
Prof Ian Day (Not used 0, Not used 0), Prof Debbie A Lawlor (Not used 0, Not used 0), George Davey-Smith (Not used 0, Not used 0)
Title of project: 
Examination of the relationship between SNPs in genes encoding insulin signalling proteins and insulin resistance
Proposal summary: 

Insulin-dependent (type I) and non-insulin-dependent (type II) diabetes remain diseases of significant unmet medical need. The long-term aim of the PI's work is to define the molecular basis by which insulin brings about its metabolic effects on cells, with a specific interest in the stimulation of glucose transport. Understanding insulin action at the molecular level in health and disease, is essential to identifying novel therapeutic regimens for treating both forms of diabetes.

Insulin action on glucose uptake involves the translocation of the insulin responsive glucose transporter, GLUT4, from intracellular storage sites to the plasma membrane and while many of the potential signalling and vesicle trafficking components have been identified, precisely how they contribute to the regulated translocation phenomenon is not yet fully understood.

The translocation of GLUT4 to the plasma membrane in response to insulin requires the activation of a complex array of signalling events. Centrally involved are the activation of phosphoinositide 3-kinase (PI3-kinase), the subsequent generation of the phosphoinositide lipid PI(3,4,5)P3 (PIP3) in the plasma membrane, and the consequent recruitment and activation of protein kinase B (PKB/Akt) via its phosphorylation on Thr308 by 3-phosphoinositide-dependent kinase-1 (PDK1) and Ser473 by TORC2.

There is now a considerable body of evidence to suggest that PKB plays a central role in insulin-stimulated glucose uptake. Much of our most recent work, therefore, has focussed on examining the role of PKB substrates in insulin-stimulated glucose uptake. This includes the proteins PIKfyve and AS160. AS160 is actually derived from two related proteins expressed from the Tbc1d1 and Tbc1d4 genes. These two proteins play a critical role in insulin action on glucose uptake.

Recent advances in genome sequencing and the analysis of single nucleotide polymorphisms (SNPs) are providing significant new opportunities to uncover the genetic basis of disease, particularly for those which are polygenic in nature such as type II diabetes. In collaboration with Profs George Davey Smith, Debbie Lawlor and Ian Day, genetic epidemiologists in the MRC Centre for Causal Analyses in Translational Epidemiology in Bristol, we have undertaken an initial examination of the Wellcome Trust Case Controlled Consortium data for associations between type II diabetes and the frequency of SNPs in genes encoding proteins that form part of the PI3-kinase signalling pathway alluded to above. This involved analysing comparative plots of data from eight major disease genome-wide association scans and noting the presence of a prominent cluster of significantly associated SNPs specific for type 2 diabetes, but not other diseases. Using this method, non-coding SNPs in both the Tbc1d1 (Chr 4) and Tbc1d4 (Chr 13) isoforms of AS160 show an association with type II diabetes at the 1/300 to 1/1000 significance levels. While lower than the significance level expected in a genome-wide scan, the conjunction of such signals in two genes within one signalling pathway strengthens the case to follow up the finding in more depth. The significance of the observation is also enhanced because an association between a coding variant in Tbc1d1 and obesity risk in females has been previously reported.

Date proposal received: 
Monday, 3 March, 2008
Date proposal approved: 
Monday, 3 March, 2008
Keywords: 
Genetics
Primary keyword: 

B622 - Large scale lymphoblastoid cell line approaches from genetical genomics to systematic biological studies - 03/03/2008

B number: 
B622
Principal applicant name: 
Prof Ian Day (University of Bristol, UK)
Co-applicants: 
Title of project: 
Large scale lymphoblastoid cell line approaches, from genetical genomics to systematic biological studies
Proposal summary: 
Date proposal received: 
Monday, 3 March, 2008
Date proposal approved: 
Monday, 3 March, 2008
Keywords: 
Genetics
Primary keyword: 

B620 - Replication of new variant rs12508460 associated with inherited predisposition to obesity - 21/02/2008

B number: 
B620
Principal applicant name: 
Dr Albert Tenesa (University of Edinburgh, UK)
Co-applicants: 
Prof Malcolm G Dunlop (Not used 0, Not used 0), Harry Campbell (University of Edinburgh, UK)
Title of project: 
Replication of new variant (rs12508460) associated with inherited predisposition to obesity
Proposal summary: 

The colon cancer genetics group (CCGG) lead by Professor Malcolm Dunlop and Harry Campbell has performed a genome-wide association study (WGAS) of colorectal cancer (CRC) risk using the Illumina HumanHap300 and HumanHap240S chips. In addition, we have performed a WGAS for obesity (BMI) on a subset of the individuals used in the CRC study. A total of 1,268 unrelated individuals were tested for ~550,000 tag SNPs. The top hit from the GWAS had an additive genetic effect of ~1kg/m2 (P = 2 x 10-6). We have performed a replication phase and a fine-mapping phase of the region on a different colorectal cancer case-control cohort comprising over 3,400 unrelated individuals. The top SNP and others from the replication phase were significant (P less than 0.05) and had an additive genetic effect of 0.34 kg/m2 which explains 0.2% of the phenotypic variant. Joint analysis of phase 1 and 2 showed that the variant was also associated with weight and waist circunference but not with height (Table 1).

Table 1. Effect estimates and significance levels of the association for the CCGG.

Trait

P

Additive effect

(SE,P)

Dominant effect

(SE,P)

% phenotypic variance explained

Weight (kg)

3.1 x 10-5

1.6

(0.41, 0.0001)

0.31 (0.52,0.56)

0.45

Height (m)

0.77

-

-

-

Waist (cm)

2.2 x 10-5

1.28

(0.33, 8.7 x 10-5)

0.22

(0.41,0.60)

0.47

We have already genotyped two replication cohorts from Croatia (N=483) and the WTCCT2D study (N=10,278). The Croatian and WTCCT2D cohorts had an additive genetic effect ranging from 0.27 to 0.43 although the association was only replicated (P less than 0.05) in the second cohort.

We would like to genotype our top hit SNP on the ALSPAC 9,000 adult women and 9,000 children, obtain access to gender, age, height, weight, DXA body fat, lean BMI, waist circunference. If repeated measures are available (specially for children) we would very much like to access them and try to model differences in patterns of growth of the different genotypes using random regression models.

We would like the genotyping to be carried out at K Biosciences, as suggested by you, since this would undoubtely be cheaper, faster and more efficient.

The main analysis will be an ANOVA comparing the genotypic mean of the three genotypes after correcting for the relevant fixed effect (ie. Gender, age, etc) but more sofisticated analysis could be performed as suggested above.

Table 2 shows that if our finding is real the ALSPAC cohort has sufficient power to replicate it.

Finally, we hope we have provided you with enough details and that you will consider our proposal favorably.

Table 2. Power to detect a QTL with population allele frequency p = 0.74. The QTL heritability was assumed to be h2QTL=0.002. The genetic model was assumed dominant for the allele that increases genotypic value. Differences in mean genotypic values were tested using an ANOVA.

Significance level

Sample Size

0.05

0.005

0.0005

10,000

greater than 0.99

greater than 0.99

greater than 0.99

7,000

greater than 0.99

greater than 0.99

0.98

5,000

greater than 0.99

0.96

0.88

3,000

0.94

0.76

0.52

1,000

0.49

0.19

0.06

500

0.27

0.07

0.02

Date proposal received: 
Thursday, 21 February, 2008
Date proposal approved: 
Thursday, 21 February, 2008
Keywords: 
Genetics
Primary keyword: 

B619 - Genome wide association scan for behavioural laterality - 18/02/2008

B number: 
B619
Principal applicant name: 
Dr Sarah Medland (Not used 0, Not used 0)
Co-applicants: 
Dr Dave Evans (University of Bristol, UK)
Title of project: 
Genome wide association scan for behavioural laterality
Proposal summary: 

BACKGROUND AND SIGNIFICANCE

Behavioural laterality (which encompasses hand, foot and eye preference and relative skill) is one of the earliest developing and oldest behavioural traits. Hand preference is first demonstrated at between 9-10 weeks gestational age as embryos begin to exhibit single arm movements [1]. From a neuropsychological perspective lateralization in the form of hand or foot preference remains the best behavioural predictor of language and emotional lateralization [2,3]. Heritability estimates from studies of twins and their non-twin siblings have found evidence of moderate genetic effects suggesting 26% of the variance in hand preference at the population level is due to additive genetic gene effects (95% Confidence Intervals: 14.8-29.9%) with the remaining 74% of variance (95%CI: 70.1-78.4%) due to unshared environmental effects [4,5]. Significant associations have been found with the Androgen receptor (Xq11-12) [6] and LRRTM1 (2p12) [7].

While laterality appears to develop prenatally exposure to adverse environments or pathogenic insults has been hypothesised to increase the prevalence of left handedness creating phenocopies [8]. Hemiparesis and gross skeletal injuries are obvious pathological causes of changes in laterality. However, more subtle neurological insults may also result in lasting changes in lateralization without deficits in other neuropsychological domains [9]. A wide range of pathogenic risk factors have been proposed, including but not limited to, maternal illness, anoxia, birth stress, low birth weight, small focused neurological injuries and ultra-sound exposure [8-16]. Unless analysis of laterality data controls for these confounds through the collection and incorporation of high quality peri-natal information it is likely that genetic effects may obscured.

Date proposal received: 
Monday, 18 February, 2008
Date proposal approved: 
Monday, 18 February, 2008
Keywords: 
Genetics
Primary keyword: 

B615 - Meta-analysis of genome-wide association studies on pulmonary function measured by forced expiratory volume in Caucasian - 18/02/2008

B number: 
B615
Principal applicant name: 
Prof Tim Spector (King's College London, UK)
Co-applicants: 
Guangju Zhai (Not used 0, Not used 0)
Title of project: 
Meta-analysis of genome-wide association studies on pulmonary function measured by forced expiratory volume in Caucasian
Proposal summary: 

We and others previously reported that pulmonary function measured by the ratio of measured to predicted forced expiratory volume in one second (FEV1) - percent predicted FEV1(ppFEV1), which is used to diagnose chronic obstructive pulmonary disease (COPD) and asthma, is highly heritable. To identify specific genetic factors influencing on ppFEV1, we conducted a prospective meta-analysis on the results of four independent genome-wide association studies in healthy Caucasian non-smoker population. We identified two chromosomal regions - 2p25.3 and 8q12.3 are interesting and may play a role in pulmonary function. we therefore selected two SNPs (rs4971396 which is located in SNTG2 on chr2 and rs7017559 which is located on chr8) within these two regions which were associated with ppFEV1 and would like to replicate the association in the ALSPAC.

Method and subjects: all the participants who are non-smokers from the ALSPAC will be inlcuded. the data of their spirometer measurementsas well as their age, height, and weight will be retrived from the existing data. predicted FEV1 will be calculated using the prediction equation derived from the US sample and the percent predicted FEV1 will then be calculated and used in the analysis. the DNA samples will be retrived and sent to the in-house laboratory to genotype for the above two SNPs.

Date proposal received: 
Monday, 18 February, 2008
Date proposal approved: 
Monday, 18 February, 2008
Keywords: 
Genetics
Primary keyword: 

B612 - Hearing in the Alspac Study participants at age 17-18 years - 03/02/2008

B number: 
B612
Principal applicant name: 
Prof Adrian Davis (Not used 0, Not used 0)
Co-applicants: 
Prof Shirley Russ (Not used 0, Not used 0), Dr Judith Gravel (Not used 0, Not used 0), George Davey-Smith (University of Bristol, UK)
Title of project: 
Hearing in the Alspac Study participants at age 17-18 years
Proposal summary: 

A. SPECIFIC AIMS

INTRODUCTION

The principal focus of this application is to obtain resources to collect detailed audiometric data on the

adolescents enrolled in the Avon Longitudinal Study of Parents and Children (ALSPAC). ALSPAC was

specifically designed to determine ways in which the individual's genotype combines with environmental

exposures and experiences to influence health and development (Golding 2001). Its strengths include use of a

total population sample unselected by disease status, and comprehensive data on children's physical, mental

and behavioral health, family and social circumstances and environmental features. In addition, a DNA bank

has been established on over 10,000 mothers and children with consent for undisclosed genetic analysis

(Pembrey 2004). ALSPAC is, therefore, uniquely positioned to explore genetic and environmental determinants

of common diseases and impairments.

Hearing loss is the commonest sensory deficit in developed countries(Davis 1989, Smith, Bale & White 2005.)

The cumulative prevalence of hearing loss in any population rises through the lifespan (Russ 2001). Hearing

loss and hearing function have been most closely studied at the extremes of life- in the neonatal period and in

old age. However, there have been very few population studies of hearing function in adolescence and even

fewer opportunities to examine the relationship between environmental factors such as otitis media, early life

risks and noise exposure and later hearing function. Similarly, very few studies have attempted genotypephenotype

correlations with respect to hearing function on a large population-based cohort, especially in

adolescence. To our knowledge, the detailed data we propose to collect on hearing in the ALSPAC 17-18 year

cohort would be the first opportunity to link detailed hearing phenotype data with genotype data on a

representative population-based sample of adolescents.

There is growing interest in the hearing function and abilities of adolescents. Widespread use of personal

listening devices such as iPods and MP3 players has heightened awareness of the potential vulnerability of

this population to the extremes of noise exposure from modern devices using current compression algorithms

(Fligor and Cox 2004). (reference - Output levels of commercially available portable compact disc players and

the potential risk to hearing.Fligor BJ, Cox LC Ear Hear. 2004 Dec;25(6):513-27)... Earler survey-based U.S.

data suggest that up to 3.4% 18-34 years olds self-report hearing problems ( NHIS 1990), while the US

National Health and Nutritional Examination Survey (NHANES) III documented 14.9% 6-19 year olds with

unilateral or bilateral losses greater than 16dBHL at low or high frequencies. (Niskar et al.1998). Consequently, we are

moving from a conceptualization of adolescence as a time when hearing is essentially intact, to one in which

considerable variations in hearing ability begin to emerge in the population. Hearing ability at any age will be

sensitive to the effects of multiple risk and protective factors, both genetic and environmental.

Date proposal received: 
Sunday, 3 February, 2008
Date proposal approved: 
Sunday, 3 February, 2008
Keywords: 
Hearing
Primary keyword: 

B614 - Early life determinants of blood pressure patterns in young adults - 01/02/2008

B number: 
B614
Principal applicant name: 
Prof Alun Hughes (Imperial College London, UK)
Co-applicants: 
Prof Nish Chaturvedi (Not used 0, Not used 0), Prof George Davey Smith (University of Bristol, UK)
Title of project: 
Early life determinants of blood pressure patterns in young adults
Proposal summary: 

Early life determinants of blood pressure patterns in young adults

1. Background

1.1 The importance of blood pressure

Globally, elevated blood pressure is one of the most important risk factors for cardiovascular disease, accounting for two thirds of all stroke and a half of all coronary heart disease (CHD)1 . Blood pressure tracks throughout the lifecourse: hypertensive adults are likely to have higher than average blood pressure in youth, with the strongest tracking correlation being observed with the period of late adolescence2. Evidence that adult blood pressure is determined by factors operating in early life is strong3. These include maternal influences, such as smoking, blood pressure and breast feeding, and factors operating in childhood including salt intake and growth trajectories from birth. This latter appears to be a particularly strong determinant of subsequent adiposity, blood pressure and cardiovascular disease (CVD) risk4-10.

1.2 Early growth patterns and blood pressure

Developmentally, three critical post-natal periods have been identified: 1) the perinatal period, 2) the period of adiposity rebound and 3) puberty/adolescence. These represent periods when homeostatic set-points may be determined and when transient environmental exposures can exert long lasting effects11. The consequences of weight gain during development are complex. For example, weight gain during infancy appears to be beneficial in terms of adult risk of diabetes and CHD12-14. In contrast, adiposity rebound in childhood, particularly in low birthweight babies14 (so called accelerated growth or centile crossing) leads to an elevated risk of adult obesity, type 2 diabetes and elevated blood pressure5;10;13-18. Further, there is evidence that the earlier in childhood that this 'rebound' occurs, the greater the risk of subsequent CVD14;18. One mechanistic explanation for these observations is that rapid weight gain in childhood may result in persistently greater fat to lean mass ratio and central adiposity in adulthood19. This suggestion is of particular importance in view of the burgeoning epidemic of obesity and obesity-related disease in children in the developed world.

1.3 Limitations of brachial blood pressure

While there have been a number of longitudinal and cross sectional studies of blood pressure (BP) in childhood and adolescence20-22; all of these studies have been based on measurements of brachial blood pressure at rest. Although brachial blood pressure clearly predicts CVD in adults23, it is an imperfect measure, and has limitations as a measure of the BP experienced by the heart and cerebral circulation24 for a number of reasons. These are discussed below.

1.3.1 Brachial versus central blood pressure

Central (aortic) pressure appears to be a better predictor of CHD than brachial pressure25-27. On average BP measured in the brachial artery exceeds aortic or 'central' blood pressure by ~10mmHg 28, however the magnitude of difference between brachial and central BP is highly variable and is actually greater in young, fit individuals29-31. Sometimes this difference in brachial and central BP is so extreme that it results in a spurious diagnosis of hypertension in youth31-33. These observations suggest that brachial measurement of BP in young people may significantly underestimate relationships between early life events and central BP as a result of confounding by spurious augmentation of brachial BP. Consistent with this, one study of children aged 7-18 years attending paediatric outpatients34 reported that low birth weight was associated with increased central blood pressure and increased central augmentation index (AIx; a indicator of wave reflection). Increased AIx was associated with low birth weight independently of age, gender, diastolic BP, heart rate and current height, but the influence of current weight was not examined and relationships to measures of growth trajectory were not assessed.

1.3.2 Resting versus ambulatory blood pressure

Ambulatory blood pressure over a 24 hour period provides a more comprehensive assessment of blood pressure burden, and is generally a stronger predictor of cardiovascular outcomes than clinic measures, even in the general population35. Further, nocturnal blood pressure may be more informative in predicting risk, in part as loss or reversal of nocturnal blood pressure dipping is associated with an adverse CVD risk factor profile 36,37, and with increased arterial stiffness38. More recently, exaggerated blood pressure variability, particularly at night (assessed as the standard deviation of blood pressure), has also been shown to increase CVD risk, independently of absolute nighttime pressure39. Many of these phenomena have also been observed in youth; ambulatory blood pressure is superior to clinic measures in detecting disordered blood pressure patterns and associated measures of target organ damage 40,41. However, determinants of these altered 24 hour patterns have been less well studied and are conflicting. For example, whilst some studies shown an association between loss of nocturnal blood pressure dipping and obesity42, others do not43. Similarly, reports of associations between blood pressure variability and birthweight are inconsistent 44,45. As above, detailed assessment of growth trajectory, and other early life influences have not been comprehensively studied in association with blood pressure patterns in youth, but may account for the discrepancies observed.

1.3.3 Static versus dynamic blood pressure measurements

An exaggerated BP rise in response to exercise or dynamic pressor tests predicts the development of hypertension46-49, and stroke risk, independently of resting BP50. These independent associations may be due to impaired exercise induced vasodilation, as a consequence of arterial wall remodelling resulting in increased peripheral vascular resistance51;52 or endothelial dysfunction53, but early life determinants of dynamic blood pressure responses, and their associations with large artery structure and function, have not been studied.

1.4 The impact of blood pressure on the vasculature

Chronic elevated blood pressure is associated with increased pulse wave velocity (PWV; an indicator of arterial stiffness) and increased intima-media thickness (IMT) of large blood vessels, such as the carotid or femoral artery. These changes have been associated with subsequent cardiovascular risk, independent of other risk factors, including blood pressure itself, and have therefore acquired the status of surrogate CVD endpoints54-58. Obesity in youth and elevated blood pressure have been associated with increased thickness of the carotid artery wall in adolescence and early adulthood59-60. However associations between risk factors (e.g. maternal blood pressure and childhood growth) and arterial stiffness in youth have been inconsistent, with some studies showing the anticipated inverse relationship with, for example birthweight7 61, while others have shown no relation or counter-intuitive relationships with growth or maternal blood pressure 62, 6364. No study has explored the association between detailed early growth patterns, blood pressure and arterial wall thickness and stiffening, which may help to account for some of the inconsistent previous findings, and help to determine how these parameters influence structure and function of the large vessels.

In summary, elevated blood pressure in adolescence, tracks to adult blood pressure and subsequent CVD risk. Key determinants of blood pressure operate in early life, in particular growth trajectories, but the exact role of these determinants is unclear, and their relations with structural and functional aspects of the large vessels inconsistent. In part, previous studies may have been confounded by marked differences between brachial and central BP that are common in youth and failure to capture the full complexity of blood pressure patterns, including circadian patterns of BP, the inherent variability of BP and response to stressors. In addition, previous studies have not had a comprehensive assessment of maternal and early life influences in a sufficiently large study sample. We propose to measure such detailed aspects of BP, including central BP, wave reflection, arterial stiffness, ambulatory BP, ambulatory arterial stiffness index (AASI) 65 and dynamic BP responsiveness and relate these to key determinants such as early life influences, particularly post-natal growth trajectories and current obesity, and with surrogate CVD outcomes (i.e. carotid IMT, PWV) in the ALSPAC cohort.

Date proposal received: 
Friday, 1 February, 2008
Date proposal approved: 
Friday, 1 February, 2008
Keywords: 
Cardiovascular
Primary keyword: 

B613 - FADS2 SNPs omega-3 fatty acids and childrens mental development - 01/02/2008

B number: 
B613
Principal applicant name: 
Dr Pauline Emmett (University of Bristol, UK)
Co-applicants: 
Prof Jean Golding (University of Bristol, UK), Alex Richardson (Not used 0, Not used 0), Prof George Davey Smith (University of Bristol, UK)
Title of project: 
FADS2 SNPs, omega-3 fatty acids and children's mental development
Proposal summary: 

Aims and Objectives

*1. In the proposed study funded by the Waterloo Foundation we will (a) assay the maternal and infant DNA for the two SNPs that Caspi considered in regard to breast feeding and IQ (rs174575 and rs 1535). (b) take the statistical models used for the ALSPAC study which showed associations between maternal seafood intake and childhood cognitive and behavioural outcomes (see Lancet paper of 2007) and determine whether such relationships are conditional upon the maternal or infant genotypes; and (c) test the finding of Caspi et al in regard to a breast feeding effect on IQ only apparent if the child has a particular genotype.

Date proposal received: 
Friday, 1 February, 2008
Date proposal approved: 
Friday, 1 February, 2008
Keywords: 
Diet, Eating disorders
Primary keyword: 

B611 - Validation and Replication of Genetic Variants in Predicted microRNA Binding Sites and their Effect on mRNA Expression Levels - 31/01/2008

B number: 
B611
Principal applicant name: 
Dr Cecilia Lindgren (University of Oxford, UK)
Co-applicants: 
Nick Timpson (University of Bristol, UK), Mahim Jain (University of Oxford, UK)
Title of project: 
Validation and Replication of Genetic Variants in Predicted microRNA Binding Sites and their Effect on mRNA Expression Levels
Proposal summary: 

Scientific case for doing the genetic association study in ALSPAC (up to about three pages) :

Genetic variation is associated with mRNA expression levels in a heritable fashion and has been mapped in humans and model organisms as expression quantitative trait loci (eQTL). We have previously determined a number of associations between genetic variation in microRNA (miRNA) binding-sites and target mRNA expression levels.We have identified 18 genetic variants in miRNA binding-sites that are significantly associated with target gene expression levels after stringent permutations in the HapMap CEU samples and that replicate in other populations and on multiple platforms. For five miRNA binding-site variants, we are able to narrow the interval of association of which two are the most associated variants in the region. This is consistent with the hypothesis that this is the true regulatory variant. Furthermore, we find an over-representation of significant miRNA binding SNPs associated with target mRNA expression levels compared to most other annotation classes.

Given the initial evidence that SNPs within microRNA binding sites effect mRNA expression levels, we hope to further replicate these findings in other samples. The ALSPAC dataset serves as an excellence and unique resource for this endeavour.

Date proposal received: 
Thursday, 31 January, 2008
Date proposal approved: 
Thursday, 31 January, 2008
Keywords: 
Genetics
Primary keyword: 

B609 - 1958 cohort - application for continued funding for processing and distribution of DNA and cell lines - 29/01/2008

B number: 
B609
Principal applicant name: 
Dr Susan Ring (University of Bristol, UK)
Co-applicants: 
Prof Ian Day (University of Bristol, UK)
Title of project: 
1958 cohort - application for continued funding for processing and distribution of DNA and cell lines
Proposal summary: 

Introduction and rationale

The British 1958 birth cohort1 is based on all persons born in Britain during one week in March in 1958. Participants have been followed throughout their lives and biomedical information has been collected at various time points. Biological samples were collected from the cohort during medical examinations between Sept 2002 and March 2004. Funding for creation of a blood derived DNA bank was provided by the MRC (strategic project grant G0000934). Funding for creation of lymphoblastoid cell lines, cell line derived DNA extraction, banking and distribution was funded by the Wellcome Trust (grant no 068545).

DNA and cell line banks were created in the ALSPAC Laboratory. Blood derived DNA is available from 8018 individuals and has been used successfully in several genotyping studies.

Cell lines from 2288 individuals were created at ECCAC, Porton and a further 5239 in the ALSPAC laboratory. DNA has been extracted from all of these samples and has been organised into geographically representative subgroups of samples specifically for use as control samples in case control studies. Samples have been distributed to over 20 collaborators and were used as control samples by the Wellcome Trust Case Control Consortium2.

Further funding was obtained in 2006 and extended in 2007 for management of the cell line and DNA banks and distribution of samples (grant number GR079996). This funding will end on 31st May 2008 and we are therefore applying for additional funds to continue these functions.

The ALSPAC laboratory

The ALSPAC Genetic Epidemiology Laboratory is part of the Department of Social Medicine, University of Bristol. The department has a strong track record in genetic epidemiology. The department currently has custodianship of samples for the Avon Longitudinal Study of Parents and Children (ALSPAC), Caerphilly, Speedwell, Boyd Orr, Christs Hospital, Barry-Caerphilly studies.

The ALSPAC laboratory is equipped to create and manage biological sample, DNA and cell line banks and currently actively manages sample collections for ALSPAC and the 1958 birth cohort. The ALSPAC laboratory team works closely with the Bristol Genetics Epidemiology Laboratory (BGEL www.bgel.genes.org.uk) which was established by Professor Ian Day in 2004. The group also has a bioinformatics core led by Dr Tom Gaunt.

Prof George Davey-Smith is director of ALSPAC and has recently been awarded an MRC centre CAiTE - Centre for Causal Analyses in Translational Epidemiology, which opened in September 2007. The centre has recruited 5 academics working in the genetic epidemiology field hence increasing the expertise in this area within the department.

The ALSPAC, BGEL and MRC Centre laboratories and sample stores will move to a new purposed designed facility in summer 2008.

The laboratory is equipped for high throughput cell line production and DNA processing. Two custom designed robotic cell maintenance systems are used for lymphoblastod cell line growth. Two DNA processing robots (Tecan Genesis Freedom 2000, and Beckman Biomek 2000) are used to quantitate DNA samples with picogreen, normalise the concentration, and prepare plates for distribution to genotyping centres. A Quadra 96SV is also available for production of 384 well plates.

The laboratory is licensed by the Human Tissue Authority for storage of human tissue for research purposes and has developed custom designed Laboratory Information Management System to log processes and track samples. Samples are stored in secure cryostores and freezer stores. These are alarmed and a member of staff is contactable automatically 24hrs a day in the event of a freezer failure to prevent loss of samples.

The laboratory is a member of the Public Population Project in Genomics (P3G) DNA quantification project that was set up in 2006 to establish internationally recognised standards in DNA quantification. DNA samples from the laboratory have been successfully genotyped in a number of different laboratories using a variety of methods including the Affymetrix 500K human mapping array and Illumina Human Hap550 genotyping Bead Chip high throughput systems.

Genotyping

The laboratory distributes DNA to collaborators for genotyping although for simple SNP genotyping for the ALSPAC study we have established links with K Biosciences (http://www.kbioscience.co.uk/). The company hold stocks of DNA from the ALSPAC cohort and collaborators are encouraged to use the company. This is cost effective in terms of DNA use and genotyping costs and has simplified quality control processes. We propose to set up a similar arrangement for investigators using 1958BC DNA.

Receipt and storage of genotyping data and quality control The Laboratory has experience of handling genetics data.All genotyping data generated from ALSPAC study samples is returned to the laboratory and incorporated into an Oracle database. Before inclusion various quality control checks are run on the data including ensuring data is in Hardy-Weinberg Equilibrium and comparisons of genotypes from duplicated samples specifically included in sample sets for quality control purposes. Where data do not appear to be of suitable quality the problems are discussed with the genotyping laboratory and appropriate steps taken to improve the results. Documentation regarding the genotyping method and outcome of quality control checks is stored with the data.

Proposal for 1958 Sample ManagementAdministrative duties for 1958BC Interim Oversight Committee

All proposals to use 1958BC DNA need to be approved by the 1958BC Interim Oversight Committee. Dr Ring represents the Bristol laboratory on the committee and Dr Wendy McArdle will continue to advise regarding the feasibility of providing samples to users and technical advice regarding proposals.

Completion of a Material Transfer Agreement (MTA) is necessary before samples can be released to users. We understand that Professor Paul Burton's group in Leicester will undertake the administration associated with MTAs but they will continue to be signed off by the University of Bristol.

Ethical Approval

An application to extend the current ethical approval to include generic approval for genetic analysis, similar to that in place for the ALSPAC study will be coordinated by the Bristol team in order to allow the transfer of genetics data to Bristol and distribution to collaborators as approved by the Interim Oversight Committee.

DNA Bank Management

DNA has been extracted from all blood samples and cell lines although the yield from some samples was lower than others. Our current funding has covered extraction of further cell line pellets from low yield samples but only from those cell lines originally prepared in Bristol. By June 2008 there will be at least 400mg of DNA available from all such cell line samples but stocks of some ECCAC prepared cell lines are significantly lower. The maximum amount of DNA distributed from any sample in the last 12 months is 20mg. Therefore no further extractions will be necessary from the samples established in Bristol in the next 2 years assuming requests continue at a similar rate. However further regrowth and extraction of some of the 2288 samples produced at ECCAC will be required. Stocks of these cell lines were transferred to Bristol recently to enable us to restock the DNA bank when necessary.

DNA Distribution

We will continue to distribute DNA to users who have been approved by the 1958 Interim Oversight Committee. Dr Wendy McArdle will continue to liaise with users regarding supply of samples and any technical issues.

DNA is supplied to collaborators either as standard issue plates (1micro-g per well at 50ng/ micro-l) or at bespoke concentrations and volumes for large genotyping projects. In the last 12 months we have supplied 21 standard issue plates and prepared 5 bespoke requests. We anticipate that the level of requests for DNA will increase in the next 24 month period as results from genome wide association studies become available. We will continue to maintain a stock of "standard issue" plates for immediate issue from stock to collaborators and where necessary prepare samples at bespoke concentrations and volumes for large genotyping projects. Receiving laboratories will continue to be asked to cover the cost of transport. Requests for "cherry picked" samples, ie provision of a subset of samples which need to be individually picked from stock plates rather than an aliquot of all samples in a given plate can be accommodated. However, we would need to ask the requestor to cover the costs of the additional staff time involved in sample preparation as we have done for such requests in the past.

In addition we will set up an arrangement for providing a single SNP genotyping service withK Biosciences (http://www.kbioscience.co.uk/) if required. A stock of 1958BC DNA will be sent to the company and orders for genotyping placed via the Bristol laboratory in order to ensure that all genotyping has been approved by the 1958BC Interim Oversight Committee. In order to test this set up and associated quality control monitoring we have asked for funds to run 5 SNP genotypes on all samples. Details of the SNPs selected will be submitted to the oversight committee for approval before genotyping.

Please note that for some requests we require information about previous genotyping or phenotypes in order to select specific samples or plates of samples. We do not have access to this information in Bristol and are currently advised which samples are required by Professor David Strachan. In order to continue to provide samples selected on the basis of phenotype or previous genotyping results we will need to be advised by someone who has in depth knowledge of all 1958 data. We understand that the Centre for Longitudinal Studies will provide this support since the Bristol team currently have no access to phenotypic data.

Receipt of Genetics Data

The Bristol group has considerable experience of handling genetics data. If required we would set up systems similar to those used for the ALSPAC study to handle genetics data for the 1958 cohort. Quality control checks will be carried out including comparison of results from control samples and verifying that results are in Hardy Weinberg Equilibrium. Any problems highlighted by the quality control checks will be discussed with the genotyping lab and genotyping repeated or excluded if necessary. Results will be stored on a genetics results database designed specifically for the 1958 cohort study but based on the design of systems currently used in the laboratory. Data would be released in agreed formats when necessary. If required summary data can be provided via a website. Several Bristol staff currently have the expertise to oversee the development of such quality control, database and web site management but such processes are time consuming therefore we would require funding for a full time researcher to develop and manage the system and a fulltime data preparation assistant to assist with data cleaning and distribution.

Cell Line Bank Management

The cell line bank is established and aliquots of all cell lines are stored in Bristol with backups stored at ECCAC, Porton Down. Samples will continue to be kept in a viable condition in secure cryovessals. Sample will be regrown to replenish DNA stocks as described above. No costs for regrowth and provision of cell lines for other purposes, eg expression studies, have been included in this proposal but such studies could be facilitated if extra funds were made available to cover the staff and consumable costs.

The costs of back up storage at ECCAC are covered until December 2010 from previous 1958 funding therefore no further contribution to cover ECCAC costs is required for the duration of this proposal.

Storage of Biosamples

If required the Bristol laboratories would be able to store and distribute other biological samples held by the 1958BC. Costs have been included to cover storage of samples; distribution costs would need to be assessed on a case by case basis.

Date proposal received: 
Tuesday, 29 January, 2008
Date proposal approved: 
Tuesday, 29 January, 2008
Keywords: 
Genetics
Primary keyword: 

B616 - Technology use privacy and teenagers - 25/01/2008

B number: 
B616
Principal applicant name: 
Adam Joinson (University of Bath, UK)
Co-applicants: 
Title of project: 
Technology use, privacy and teenagers
Proposal summary: 

Aims and objectives

Identity and privacy have recently rarely been out of the headlines. Government has justified the need to identify

citizens and track behaviour or security reasons, and promoted data sharing with the promise of the benefits of

transformational government. Business argues that it needs to track customer behaviour both in the real world and the

Internet to deliver personalised services that offer more targeted information and identify new business opportunities.

The public is generally portrayed as unconcerned about privacy: based on opinion poll data, government argues that the

majority of citizens support identification and surveillance, and commercial companies argue that customers are happy

to volunteer detailed information about themselves in return for discounts or entry in a prize draw. In a recent report, the

UK Information Commissioner characterised the situation as Sleepwalking into a Surveillance Society.

Do citizens and customers really not care? Previous research has shown that in many situations, people opt for

immediate benefits (or promises thereof), and are less concerned about future possible risks (or not aware of them).

However, once people experience negative consequences, or discover risks they were unaware of, they tend to respond

strongly - often abandoning services and technologies involved altogether. For example, 11% of Icelandic citizens

opted out the country's DNA database after government attempts to sell access to commercial researchers (Anderson,

1998). Examples of data sharing and leakage have raised awareness how data can be used and abused. Increasingly,

people try to defend against the collection of sensitive or inappropriate data by refusing to register, or giving false

information (Dutton & Helsper, 2007). Such responses can cause significant economic damage, or - in case of large

numbers opting out or providing "fake" information - lead to a collection of data that has little or no value. Data

owners' approach has often to been collect "all the data we can get", because "you never know when it might be

useful." However, the resulting data quality is often low, and can lead businesses to make poor long-term decisions.

For instance, if a bank or phone company refuses a mortgage or phone contract to a solvent individual because of

incorrect or outdated information, this is business lost. If 50% of people interested in a service do not register because

they fear a telemarketing assault, this is a lost business opportunity. Increasing data quality and transparency on how it

is used would have significant business benefits, and an equitable, cooperative relationship between data owners and

data subjects creates the foundation for this. This is particularly important to the UK financial sector: about 10% of

adults are spending more than their monthly income, and as a result, individual insolvencies rose by 62% to 109,288 in

2006. The traditional approach of excluding anyone with a history of financial difficulty, or charging a hefty premium,

is not sustainable. Financial exclusion can lead to social exclusion because of impact in other areas of life - housing,

employment and personal relationships, so understandably, such individuals are particularly sensitive to privacy issues.

The cost and benefit of collecting and storing data about individuals has not been properly examined, and the value of

holding information about individuals for specific purposes is not understood. The project will help government and

business to understand the value of personal data, as well as the value and risks for other stakeholders. The Home

-4-

Office estimates that identity theft costs the UK £1.7bn each year, but without a proper cost-benefit analysis, it is

impossible for data-collectors to understand how, or indeed whether, to reduce the amount of data that they collect.

Research into privacy has both benefited and suffered from its multidisciplinary nature. The multitude of perspectives

and methods has led to many detailed findings, but there is still a lack of clarity of what privacy is and what it means to

different stakeholders in different contexts/scenarios of use. There has been no attempt to measure the cost and benefits

to the stakeholders involved in comparable units. Most studies are one-off surveys, 'feeling the temperature' to general

questions about privacy. There has been no study of how stakeholders' perception evolves over time, in response to

experiences of benefits and drawback of data held about them. There is a lack of quality, empirical data on these issues,

and how to collect it. The problem of collecting reliable data on people's perceptions surrounding sensitive data about

them is akin to Schrodinger's Cat - to discuss privacy, you have to reveal things you want to keep private. The goal of

the pvnets project is to develop new methodologies that enable us to break this paradox - and more specifically:

- To produce a strong empirical base for developing concepts of privacy across contexts and timeframes.

- To investigate ways in which to establish an equitable relationship between stakeholders in terms of the value

and costs inherent in the collection, processing and use of personal data.

- To develop and apply new, validated, ethical and privacy-sensitive methodologies for the study of privacy.

- To produce a toolkit to enable commerce and Government to understand the role of personal information in

business processes and enhance strategic decision-making and the value of that information to all parties.

- To support UK businesses to become world leaders in the area of trustworthy products, systems and services

Date proposal received: 
Friday, 25 January, 2008
Date proposal approved: 
Friday, 25 January, 2008
Keywords: 
Primary keyword: 

B605 - The influence of social and family factors on the developmental effects of persistent otitis media with effusion - 24/01/2008

B number: 
B605
Principal applicant name: 
Dr Amanda J Hall (University of Bristol, UK)
Co-applicants: 
Dr Fei Zhao (Not used 0, Not used 0), Dr Lindsay StClaire (Not used 0, Not used 0)
Title of project: 
The influence of social and family factors on the developmental effects of persistent otitis media with effusion.
Proposal summary: 

ALSPAC has prospective data relating to early otitis media with effusion (OME), developmental outcomes and family factors on a large, normal population of children. It is ideally placed to study the sequelae of early OME and any interaction with family factors.

Date proposal received: 
Thursday, 24 January, 2008
Date proposal approved: 
Thursday, 24 January, 2008
Keywords: 
Primary keyword: 

B766 - Genetic causes of sex differences in ADHD and schizophrenia - 23/01/2008

B number: 
B766
Principal applicant name: 
Dr Evie Stergiakouli (University of Bristol, UK)
Co-applicants: 
Prof Anita Thapar (University of Cardiff, UK), Prof Michael Owen (University of Cardiff, UK)
Title of project: 
Genetic causes of sex differences in ADHD and schizophrenia.
Proposal summary: 

Background

Many psychiatric disorders display distinct sex differences. Men are more likely to be affected by neurodevelopmental disorders, such as attention deficit hyperactivity disorder (ADHD) and schizophrenia. ADHD is a childhood onset disorder characterised by inattention, overactivity and impulsiveness. The disorder affects males more than females at a ratio of 4:1. In schizophrenia, the age of onset in men is significantly earlier (21 years) than for women (25 years). The disorder is more severe in male patients and they generally have more negative symptoms (Preston et al, 2002).

The causes of sex differences in neurodevelopmental disorders could be due to endocrine, genetic, or environmental factors and their possible interactions. In terms of genetic factors men and women differ in their sex chromosome complement and therefore the Y chromosome is potentially an important influence on male susceptibility to neuropsychiatric disorders.

Animal studies where it has been possible to disaggregate gonadal sex and sex chromosome complement have found that the Y chromosome is associated with more aggressive and less parental behaviour (De Vries et al, 2002; Gatewood et al, 2006). Possession of two Y chromosomes as in the chromosomal abnormality XYY is associated with a higher risk of antisocial behaviour when compared to those with an XXY chromosomal anomaly (Rutter et al, 2003).

However, there are difficulties in studying the Y chromosome: there is no recombination, no widely accepted nomenclature and its distribution depends highly on geographic origin (Jobling and Tyler-Smith, 2003). These difficulties have led to the Y chromosome being largely excluded from genetic and genomic studies of neuropsychiatric disorders.

To overcome this lack of knowledge surrounding the Y chromosome in psychiatric disorders, we chose to study Y chromosome variants in a sample of 210 cases with ADHD, 310 cases with schizophrenia and 700 U.K. controls.

Our hypothesis is that:

* Y chromosome haplogroups increase male susceptibility to ADHD and SZ directly

* Y chromosome haplogroups increase male susceptibility to ADHD and SZ indirectly by interacting with autosomal genes expressed in brain or environmental factors

* Y chromosome haplogroups influence sexually dimorphic cognitive performance which has a modifying effect on the disorders

Y chromosome SNPs were selected after extensive research on markers used in previous Y chromosome studies, Y chromosome Consortium data, which contain information on all the Y chromosome haplogroups (groups of haplotypes), and personal communication with research experts on the Y chromosome. These SNPs were selected in order to capture the most frequent Y chromosome haplogroups in the U.K.

Statistical analysis of Y chromosome haplogroups revealed no significantly increased representation of any haplogroup in cases with ADHD (p=0.539) or schizophrenia (p=0.679) compared to controls.

Date proposal received: 
Wednesday, 23 January, 2008
Date proposal approved: 
Wednesday, 23 January, 2008
Keywords: 
ADHD, Schizophrenia, Sexual Behaviour
Primary keyword: 

B607 - Investigating the role of type 2 diabetes genetic loci in fetal growth childhood growth and T2D intermediate traits - 23/01/2008

B number: 
B607
Principal applicant name: 
Prof George Davey Smith (University of Bristol, UK)
Co-applicants: 
Prof Tim Frayling (Peninsula Medical School, University of Plymouth, UK), Prof Mark McCarthy (University of Oxford, UK)
Title of project: 
Investigating the role of type 2 diabetes genetic loci in fetal growth, childhood growth and T2D intermediate traits.
Proposal summary: 

We wish to use the ALSPAC cohort to investigate the effects of novel and previously-confirmed type 2 diabetes loci on fetal growth, growth in childhood and intermediate traits related to type 2 diabetes.

Following our analyses of the first UK type 2 diabetes genome-wide association (GWA) study, which identified 6 new type 2 diabetes genes (FTO, CDKAL1, CDKN2A/2B, HHEX, IGF2BP2, SLC30A8) [1, 2], we have performed a meta-analysis of GWA data, combining our UK study with the DGI [3] and FUSION [4] GWA scans (N=10,128 individuals and ~2.2 million SNPs, directly genotyped and imputed). We followed-up promising signals by performing replication studies of up to 63,532 independent samples [5]. Four loci showed robust evidence for association at Pless than 5x10-8. We are therefore confident that the results exceed the stringent levels of statistical support needed for genetic association studies.

The associated SNPs are as follows:

JAZF1 rs864745

CDC123/CAMK1D rs12779790

ADAMTS9 rs4607103

THADA rs7578597

The precise nature of the biological mechanism by which each of these genes predisposes to type 2 diabetes is largely unknown. We have used replication and robust statistical data, rather than biology, to identify these genes. Further analyses of their roles in intermediate traits, using ALSPAC, are likely to help to uncover further biological pathways.

In addition to the above, we would like to complete the list of currently-confirmed type 2 diabetes loci genotyped in ALSPAC by including the following:

WFS1 rs10010131

PPARG rs1801282

KCNJ11 rs5219

We therefore propose to analyse the polymorphisms in ALSPAC to test the following hypotheses:

1. Fetal genotype and maternal genotype alter fetal growth.

2. Fetal genotype and maternal genotype alter growth velocity in childhood

3. Genotype alters intermediate traits related to type 2 diabetes including fasting insulin, fasting glucose and insulin secretion (in the subset of offspring with OGTT data), triglycerides, HDL, LDL and total cholesterol, anthropometric measures including BMI, lean/fat body mass, WHR, waist circumference, skin folds where available.

4. In the event of associations with intermediate traits in mothers we will propose to test the role of maternal genotype on fetal and childhood growth and body composition and biochemistry. For example, if the SNP alters BMI the SNP can be used in a Mendelian randomisation framework to test the role of maternal BMI in fetal growth and body composition free from confounding factors such as socio-economic status.

Whether the results are negative or positive they will help in our understanding of how the novel genes function and, if positive, provide important insights into growth and other diabetes intermediate phenotypes.

* Specific ALSPAC phenotypes being considered:

To do this we would like to genotype (at Kbioscience) all ~20,000 ALSPAC samples. We will need the following phenotypes to test our hypotheses:

1. Birth weight, length and head circumference

2. Growth measures in childhood (height, weight and BMI aged 7-11)

3. Covariates of birth weight to check if genotype is acting through them: gestational age, maternal age, maternal BMI, smoking , parity, twin status to exclude non-singletons, ethnicity as genotype frequency may alter with ethnic origin and confound analyses.

4. Type 2 diabetes-related intermediate traits including fasting insulin, fasting glucose and insulin secretion (in the subset of offspring with OGTT data), triglycerides, HDL, LDL and total cholesterol, anthropometric measures including BMI, lean/fat body mass, WHR, waist circumference, skin folds where available.

In addition, we are keen to examine the KCNJ11 variant in relation to physical activity in the ALSPAC children. This is to follow up a nominal association observed in the RISC cohort (Mark Walker, personal communication).

Plans for replication:

ALSPAC will provide the largest dataset for association studies with fetal growth. However, we have access, through our own studies and extensive collaborations to samples from the Exeter family study (950 population based parent-newborn trios), Plymouth Earlybird study (300 parent-5 yr old trios - T Wilkin) the North Cumbria community genetics project (3000 mother child pairs - C Relton), the Northern Finnish 1966 Birth Cohort (4600 individuals with own birth measures) and the 1958 cohort (7000 individuals with own birth measures). We hypothesize that real genetic associations will be consistent across all these studies - i.e. even if individually studies show only nominal significance, a meta-analysis of all studies will provide highly significant results.

Date proposal received: 
Wednesday, 23 January, 2008
Date proposal approved: 
Wednesday, 23 January, 2008
Keywords: 
Genetics
Primary keyword: 

B767 - GWAS analysis of cortical bone geometry - 22/01/2008

B number: 
B767
Principal applicant name: 
Dr Jon Tobias (University of Bristol, UK)
Co-applicants: 
Prof Claes Ohlsson (University of Gothenburg, Europe), Dr Dave Evans (University of Bristol, UK)
Title of project: 
GWAS analysis of cortical bone geometry.
Proposal summary: 

Background

Understanding of the genetic determinants of osteoporosis has recently been advanced by GWAS studies looking at associations with bone mineral density (BMD) in adults (1,2), an approach we have recently applied to ALSPAC (Timpson et al, submitted for publication). However, one of the limitations of these studies is that whereas BMD is related to the risk of osteoporotic fracture in later life, this parameter does not take account of other characteristics of the skeleton which also contribute to fracture risk, such as cortical geometry. In contrast to conventional DXA scanners, pQCT, which has been obtained in all available ALSPAC children at age 16 and is currently being repeated at age 18, can accurately measure cortical bone geometry.

Aims

We plan to conduct the first GWAS analysis of cortical bone geometry, based on pQCT data obtained in ALSPAC children.

Methods

1. GWAS analysis will be performed between results of illumina chip whole genome analysis and pQCT as measured at age 16, in all available ALSPAC children (expect around 800 with 317k chip and 800 with 610k chip). Summary statistics (beta coefficients and P values) will be derived for associations with tibial cortical BMD and periosteal circumference (50% site), adjusted for age, height, weight and gender.

2. GWAS analysis will be performed between results of 610k illumina chip and approximately 1000 18-20 year old men from the GOOD cohort (3). Summary statistics (beta coefficients and P values) will be derived for associations with tibial cortical BMD and periosteal circumference (25% site), adjusted for age, height and weight.

3. A meta-analysis will be performed based on results from ALSPAC and GOOD, following which the top 100 hits will be identified (where necessary, missing genotypes from the 317k platform will be imputed).

4. A proportion of these hits will be carried forward for selective genotyping in the following three cohorts, using a variety of selection strategies (e.g. screening markers for evidence of cis-regulation in human osteoblast cells in collaboration with T Pastinen, McGill University):-

a. Remaining ALSPAC children not included in GWAS analysis

b. MrOS Sweden (approximately 1500 elderly men with pQCT data and available DNA)

c. Hertfordshire cohort (approximately 650 subjects (men and women combined) mean age 65 approx with pQCT data and available DNA)

5. Further meta-analyses will be performed (i) combining ALSPAC GWAS, GOOD and ALSPAC replication cohorts, and (ii) combining all five cohorts

References

1. Richards JB, Rivadeneira F, Inouye M, Pastinen TM, Soranzo N, Wilson SG, Andrew T, Falchi M, Gwilliam R, Ahmadi KR, Valdes AM, Arp P, Whittaker P, Verlaan DJ, Jhamai M, Kumanduri V, Moorhouse M, van Meurs JB, Hofman A, Pols HA, Hart D, Zhai G, Kato BS, Mullin BH, Zhang F, Deloukas P, Uitterlinden AG, Spector TD 2008 Bone mineral density, osteoporosis, and osteoporotic fractures: a genome-wide association study. Lancet 371(9623):1505-12.

2. Styrkarsdottir U, Halldorsson BV, Gretarsdottir S, Gudbjartsson DF, Walters GB, Ingvarsson T, Jonsdottir T, Saemundsdottir J, Center JR, Nguyen TV, Bagger Y, Gulcher JR, Eisman JA, Christiansen C, Sigurdsson G, Kong A, Thorsteinsdottir U, Stefansson K 2008 Multiple Genetic Loci for Bone Mineral Density and Fractures. N Engl J Med.

3. Lorentzon M, Mellstrom D, Ohlsson C 2005 Association of Amount of Physical Activity With Cortical Bone Size and Trabecular Volumetric BMD in Young Adult Men:The GOOD Study. J Bone Miner res 20:1936-1943.

Date proposal received: 
Tuesday, 22 January, 2008
Date proposal approved: 
Tuesday, 22 January, 2008
Keywords: 
GWAS, Bone
Primary keyword: 

B765 - An investigation into the relationship between maternal and paternal depression over time using multilevel modelling - 22/01/2008

B number: 
B765
Principal applicant name: 
Dr Jonathan Evans (University of Bristol, UK)
Co-applicants: 
Prof John Rasbash (Deceased) (University of Bristol, UK), Prof Jennifer Jenkins (University of Toronto, Canada)
Title of project: 
An investigation into the relationship between maternal and paternal depression over time using multilevel modelling.
Proposal summary: 

Aim

We aim to explore the relationship between maternal and paternal depression over time in order understand the direction of causality taking into account reciprocal effects. A further aim is to explore how this relationship alters according to child behaviour and life stresses and finally how this relationship impacts on future child emotion and behaviour.

Method

We propose analysing the ALSPAC data up to age 8 including repeated measure of maternal and paternal mood and measures of child emotional and behavioural problems. We will begin by exploring reciprocal causation between maternal and paternal depression and investigate how this varies as a function of life stress, child behaviour, marital relationship and family size. We will use multilevel models to investigate the random slopes for lags and crosslags this represents a novel method of investigating these questions with the advantage that this more flexible statistical model can model the more complex reciprocal relationships likely to arise within families.

Variables

Our main variables will be:

Maternal Mood EPDS pregnancy 18 weeks & 32 weeks antenatally 2, 8, 21 33 61 73 and 97 months postnatally

Paternal mood EPDS pregnancy 18 weeks antenatally 2, 8, 21 33 61 73 and 97 months postnatal

Child emotional and behavioural problems - Carey infant temperament 6 months and Carey toddler temperament 24 months EAS temperament 38, 57 and 69 months Rutter parent Scale for preschool chidldren 42, 57 & 69 months SDQ 47 81 97 months.

Other variables:

Age mother

Age father

Number of children in home

Primip vs multip

Nature of delivery

SES (highest educational level mother)

Quality of Marital relationship - Intimate bond measure 21 and 33 months

Life events 18 weeks 32 weeks antenatally, 2, 8, 21 33 47, 61, 73 months.

Date proposal received: 
Tuesday, 22 January, 2008
Date proposal approved: 
Tuesday, 22 January, 2008
Keywords: 
Depression, Pregnancy
Primary keyword: 

B599 - Association of validated breast cancer susceptibility single nucleotide polymorphisms and modifiable childhood traits - 09/01/2008

B number: 
B599
Principal applicant name: 
Prof George Davey Smith (Not used 0, Not used 0)
Co-applicants: 
Prof Lyle Palmer (Not used 0, Not used 0), Ms Julie Marsh (Not used 0, Not used 0), Dr Beate St Pourcain (Not used 0, Not used 0)
Title of project: 
Association of validated breast cancer susceptibility single nucleotide polymorphisms and modifiable childhood traits.
Proposal summary: 

No outline received

Date proposal received: 
Wednesday, 9 January, 2008
Date proposal approved: 
Wednesday, 9 January, 2008
Keywords: 
Genetics
Primary keyword: 

B598 - Gene x gene and gene x enviroment interactions underlying speech language and reading development - 04/01/2008

B number: 
B598
Principal applicant name: 
Dr Silvia Paracchini (University of Oxford, UK)
Co-applicants: 
Diane Newbury (Not used 0, Not used 0), Dorothy Bishop (Not used 0, Not used 0), Mr Colin Steer (University of Bristol, UK), Prof Patrick Bolton (King's College London, UK), Prof Jean Golding (University of Bristol, UK), Prof Anthony P Monaco (University of Oxford, UK)
Title of project: 
Gene x gene and gene x enviroment interactions underlying speech, language and reading development
Proposal summary: 

e propose to conduct a gene x gene and gene x environment analysis of candidate factors that have been shown to increase susceptibility for dyslexia and SLI in previous research or that have been chosen on the basis of their biological function. We will genotype all the available ALSPAC children DNA samples (greater than 10,500) for susceptibility variants within candidate genes and conduct the analysis using cognitive outcomes and environmental exposures already assessed in the ALSPAC project.

The genotyping will be performed using the Sequenom i-plex technology in collaboration with the Genomics Core facility at WTCHG. We already have in our laboratory the sufficient quantity of ALSPAC DNA required by this project.

We will select for analysis measures of reading, language and speech abilities, including measures of single word reading, non-word reading, phoneme awareness, orthographical skills, spelling, short-term memory (including NWR), verbal expression, comprehension and IQ. Many of these measures are the same as those used in our current dyslexia and SLI linkage and association studies. We plan to include in the analysis measures of attention and hyperactivity behaviour since attention deficit hyperactivity disorder (ADHD) shows extensive co-morbidity with both dyslexia and SLI.

The environmental factors will include measures that have already been proposed as risk factors for SLI, for example otitis media with effusion (OME) and maternal education, or associated with dyslexia, for example the home literacy environment and Omega-3 fatty acid consumption. We will consider also the child's environment, more general aspects of parenting and parent-child interaction. Statistical analysis will be based on linear regression models extended to include one or more covariates. We will also interrogate for multilocus interactions and genetic effects specific to factors underlying the phenotypes using techniques such as principal component or cluster analysis. Analysis will be performed both for single SNPs and haplotypes.

A detailed list of genotypes, phenotypes and environmental measures is given in the appendix.

Strategy details

Aim 1: To investigate whether the effect of dyslexia and SLI susceptibility variants can be modulated by different genetic factors (gene x gene interactions). We will select the maximum number of SNPs that can be accommodated in three i-plex reactions. Most of the novel dyslexia candidate genes we are proposing for this project have been selected for showing a strong signal in the recent WGA analysis we conducted in 600 individuals with dyslexia collected in Germany and in the UK as part of the collaborative NeuroDys project (www.neurodys.com). Other genes have been selected for their (i) similarity to other established dyslexia candidates (KIAA0319-like), (ii) interaction with established dyslexia candidates (we have recently identified interaction between the AP2M1 and KIAA0319 proteins) or (iii) role in neuronal migration, a biological pathway to which most of the reported dyslexia candidates seem to contribute. We will also include candidate genes for ADHD since this disorder show an extensive co-morbidity with dyslexia and SLI. SNPs have been selected either for showing significant association in previous work or for tagging the most common haplotype across the genes of interest. Statistical analysis will be conducted at different levels. We will first test for association between single SNPs and quantitative measures of reading, language and speech in a linear regression framework. This analysis will enable us to prioritise further investigations on the basis of the strength of association found with each gene. Following these initial association analyses, we plan to test for gene x gene interactions between the genotyped loci for example by integrating an epistatic component into the regression model. In this second step of the analysis we will incorporate also genes for which we have already obtained ALSPAC approval*.

A specific question we aim to answer is whether any tested SNP or haplotype can modulate the effect of the KIAA0319 risk haplotype (which we have recently identified within the ALSPAC sample) and whether it is possible to detect any specific interactions between candidate genes involved in the same biological pathways, such as between genes involved in neuronal migration.

Aim 2: To investigate the role of environmental factors in modulating the effect of genes that contribute to measures of reading, speech and language (gene x environment interactions). This analysis will aim to test whether any environmental factors can modify the effect of an individual's genetic background in either a protective or adverse manner for reading and language ability. The SNPs, haplotypes and gene x gene interactions that show significant associations in Aim 1 will be tested for gene x environment interaction using the environmental measures described in the Appendix.

Aim 3: To test whether shared genetic or environmental factors can explain co-morbidity between dyslexia and SLI and whether it is possible to identify a correlation between genetic/environment background and specific sub-groups of phenotypes. The data generated in Aim 1 and Aim 2 will be used to assess whether it is possible to identify causative factors that either have a particular effect on specific phenotypes or affect different, broader areas of cognition. Factors that are found to have a pleiotropic effect across different phenotypes will be further explored to investigate a possible role in determining the observed co-morbidity between SLI, dyslexia and related disorders such as ADHD. Since both dyslexia and SLI could be hypothesised to be caused by an underlying phonological deficit it will be interesting to see if specific genes contribute to the variation of phonological outcomes. The identification of association between single factors and multiple phenotypes will lead to the question of whether it is possible to identify additional interacting factors that result in more distinctive phenotype. The ultimate aim of this analysis is to test whether it is possible to distinguish between well-defined cognitive deficits on the basis of determined genetic/environmental background.

Date proposal received: 
Friday, 4 January, 2008
Date proposal approved: 
Friday, 4 January, 2008
Keywords: 
Genetics
Primary keyword: 

B597 - Development of ear drum retractions - 21/12/2007

B number: 
B597
Principal applicant name: 
Dr Richard Sim (Not used 0, Not used 0)
Co-applicants: 
Mr David Poitier (Not used 0, Not used 0)
Title of project: 
Development of ear drum retractions
Proposal summary: 

Background

Disorders of the tympanic membrane (ear-drum) such as perforation, scarring, thinning and retraction are commonly found on routine ear examination in both symptomatic and asymptomatic patients. In many cases these conditions will have no long-term detrimental effects and some will resolve spontaneously. However, in many cases of retraction, progression will occur resulting in deafness, discharge from the ear and in some cases meningitis, intracranial infection and even death. It is not currently possible to identify which patients with retractions may run into problems and which ones will be stable or improve in the longer term. This means that many patients are followed up in clinic unnecessarily, whilst those that may benefit from closer surveillance, allowing timely intervention if progression of disease is seen, or early intervention as prophylaxis against disease development, are often not identified until damage has been done to the ear and hearing. In the meantime these patients may suffer with infection, discharge and intermittent or progressive deafness, often having significant lifestyle impact on top of the long-term risk to hearing and health. The ability to identify those patients at risk of complications would, potentially, have significant long-term health and lifestyle benefits.

Methods

As part of the focus group, 8,000 children from ALSPAC have undergone regular assessment of their hearing. At a previous assessment, 7,250 children had digital photographs taken of their eardrums showing thepars flacida(top of eardrum) andpars tensa(main part of ear drum); these have subsequently been analysed for the presence of abnormalities as shown below:

Area

No retraction

Retraction

Moderate / Severe disease

Pars Flacida

13,704

558

271

Pars Tensa

13,918

444

113

In the first instance the group of children identified as having a moderate / severe retraction will be invited for a clinical review with repeat photographs of the eardrum taken. A cohort from the group previously identified as normal will be assessed in the same clinics.Ethical approval will be obtained from ALSPAC and from the local regional ethical committee. Appropriate information sheets will be provided with the initial invitation to attend and consent forms completed at the time of review.

The letters would be sent by ALSPAC, replies would collected by ALSPAC, and only those that confirm their desire to participate will have their details supplied to the research team. The research team would then use NHS resources to book appointments.

Transport costs will be paid and a voucher offered as an incentive to attend. Review will be undertaken in the ENT department at St Michael's Hospital by one if the investigating team, either in a regular ENT clinic or a specific research clinic; if it is more convenient for those invited, clinics will be undertaken at a peripheral site, e.g. Weston General Hospital, assuming local approval. If possible we would like to identify some children of interest who are part of the ALSPAC cohort and are already due for ENT assessment or review to act as a pilot study. We would aim to do this by obtaining consent from patients seen in the clinic, who may be part of the relevant focus group, to contact ALSPAC to see if data is held on them. Since the children would have already been reviewed and appropriate clinical information obtained, costs would be kept to a minimum. If this approach is unsuccessful, we would seek ethical approval to obtain the NHS Numbers from ALSPAC of the young people identified previously, and attempt to match those with young people already booked for ENT examination in one of the main hospitals. A pilot study would allow us to fine-tune our study and subsequently apply for substantial funding for the review of the remaining children

If significant disease is identified at review, the child's GP will be contacted to arrange further assessment.

AnalysisDigital photographs will be analysed and classified in the same way as the original images. Comparison will be made between individuals with regard to whether the previously documented retraction has progressed, stayed the same or improved. ALSPAC data will be analysed to identify potential risk factors for disease progression.

This study will eventually describe changes in retraction pockets in a cohort of approximately four hundred patients over a six-year period. It will identify three possible outcomes: improved, stable or progressed. Identifying changes in these patients will allow appropriate clinical follow up if not already arranged and will identify a cohort of patients suitable for further analysis of a variety of potential risk factors, including environmental and genetic

Date proposal received: 
Friday, 21 December, 2007
Date proposal approved: 
Friday, 21 December, 2007
Keywords: 
Hearing
Primary keyword: 

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