Developmental language disorder - heritability and genetic correlations with other disorders affecting language.

Developmental language disorder (DLD) is a neurodevelopmental disorder primarily affecting language in the absence of a known biomedical condition, which may have a large impact on a person's life and mental health. Family-based studies indicate a strong genetic component in DLD, but genetic studies of DLD are scarce. In this study we estimated the heritability of DLD and its genetic correlations with related disorders and traits in sample of >25,000 individuals from the Danish Blood Donor Study for whom we had both genotype data and questionnaire data on language disorder and language support.