Based on the results of our GWAS, we are interested in further dissecting the relationship between handedness and neurodevelopmental disorders such as dyslexia. We found an association between relative hand skill and PCSK6, specifically in individuals with dyslexia. Inclusion of individuals from ALSPAC with SLI and ADHD resulted in a stronger association. We are proposing to analyse the ALSPAC GWAS data for the pegboard measure specifically in those individuals we previously identified as having dyslexia, specific language impairment (SLI), or attention deficit hyperactivity disorder (ADHD).

We would first analyse those individuals defined as having dyslexia (N=238) genome-wide, then perform a meta-analysis with our own GWAS data. Following this, we can then replicate individual SNPs in our sample of unrelated dyslexic cases characterised with the pegboard measure (N=385). We will then extend the analysis to the larger group classified for neurodevelopmental disorders including SLI, ADHD and comorbid cases.

Our hypothesis is that the genetic basis of handedness, cerebral asymmetry and neurodevelopment are interlinked. SNPs associated with handedness in individuals with a neurodevelopmental disorder such as dyslexia may therefore be different to associated SNPs in a general population cohort.