Details of Genomewide Association Results, Protocol, Statistical Analysis, and Additional References (Harlaar et al., 2014)

<b>Purpose </b>Researchers have previously shown that individual differences in measures of receptive language ability at age 12 are highly heritable. In the current study, the authors attempted to identify some of the genes responsible for the heritability of receptive language ability using a genome-wide association approach. <br><b>Method </b>The authors administered 4 Internet-based measures of receptive language (vocabulary, semantics, syntax, and pragmatics) to a sample of 2,329 twelve-year-olds for whom DNA and genome-wide genotyping were available. Nearly 700,000 single-nucleotide polymorphisms (SNPs) and 1 million imputed SNPs were included in a genome-wide association analysis of receptive language composite scores. <br><b>Results </b>No SNP associations met the demanding criterion of genome-wide significance that corrects for multiple testing across the genome ( <i>p</i> &lt; 5 × 10−8). The strongest SNP association did not replicate in an additional sample of 2,639 twelve-year-olds. <br><b>Conclusions </b>These results indicate that individual differences in receptive language ability in the general population do not reflect common genetic variants that account for more than 3% of the phenotypic variance. The search for genetic variants associated with language skill will require larger samples and additional methods to identify and functionally characterize the full spectrum of risk variants.