Genetics of specific reading and language disorders. (360G-Wellcome-076566_B_05_Z)

Evidence from twin and family studies has indicated a strong genetic component in specific language impairment (SLI) and specific reading disability (dyslexia). We have completed whole genome scans to identify genes giving rise to susceptibility in each disorder using a family based quantitative trait loci (QTL) approach and replicated our linkage results for four loci in independent sets of families. We propose to further analyse the regions of strong linkage with an association strategy to identify susceptibility genes. To achieve this aim we propose to collect 300-500 cases for each disorder to replicate association of specific alleles at candidate genes in the regions of linkage. We have evidence for a candidate gene associated with dyslexia and chromosome 6p22 and propose to identify two other QTLs on chromosome 18 for dyslexia and chromosome 16q24 for SLI. Genes will be further characterised for gene regulation and function based on existing knowledge of these genes and a number of experimental approaches. The overall aim is to understand the neurodevelopmental pathways implicated in the disorders and to provide better diagnostic tools and insight into potential therapies.