Decoding the genetics of speech and language

Researchers are beginning to uncover the neurogenetic pathways that underlie our unparalleled capacity for spoken language. Initial clues come from identification of genetic risk factors implicated in developmental language disorders. The underlying genetic architecture is complex, involving a range of molecular mechanisms. For example, rare protein-coding mutations of the FOXP2 transcription factor cause severe problems with sequencing of speech sounds, while common genetic risk variants of small effect size in genes like CNTNAP2, ATP2C2 and CMIP are associated with typical forms of language impairment. In this article, we describe how investigations of these and other candidate genes, in humans, animals and cellular models, are unravelling the connections between genes and cognition. This depends on interdisciplinary research at multiple levels, from determining molecular interactions and functional roles in neural cell-biology all the way through to effects on brain structure and activity.

► Genes involved in language deficits offer gateways into neurobiology of a unique human trait. ► Mixed aetiology: rare protein-coding changes (FOXP2), common polymorphisms (CNTNAP2, etc.). ► Candidate genes studied in cell models, animals (birds, rodents), humans (neuroimaging genetics). ► Effects of language-related genes extend between disorders, and beyond into normal variation. ► Interdisciplinary efforts involving geneticists, neuroscientists, psychologists and linguists.