Watch your language!

Several studies have suggested that there may be a genetic component to developmental disorders of speech and language, but no specific genes have been identified. In the October 4 Nature, Cecilia Lai and colleagues at the University of Oxford report mutations in a gene that correlates with such language disorders (Nature 2001, 413:519-522). Study of a family (called KE) with speech-language disorder led to the mapping of the SPCH1 locus on chromosome 7. Lai et al. performed fluorescence in-situ hybridisation (FISH) analysis to map a translocation breakpoint within this region in an unrelated patient with a similar disorder. This led them to the FOXP2 gene, which encodes a novel protein with a polyglutamine tract and a forkhead/winged-helix (FOX) DNA-binding domain. They also identified a point mutation (causing an arginine-to-histidine substitution) in the FOXP2 gene in the KE family that segregated with the language disorder. Mutations in other FOX genes have previously been associated with a range of genetic disorders.