Several single genes and copy number-variant conditions are now associated with CAS either in relative isolation, as in the case of FOXP2 variants, or most typically in association with other neurodevelopmental conditions, such as epilepsy, intellectual disability, motor impairment and autism.
The results of this study suggest that common variants of FOXP2 are unlikely to contribute to autism susceptibility, in agreement with previous findings.
Expression of several genes associated with schizophrenia or autism including Sema3a, Trfr2 and Vldlr were found to be altered as were protein levels of Foxp2.
Using an intra-family association design, we identified no transmission disequilibrium in any of the four identified alleles, suggesting that the FOXP2 gene does not play a significant role in AD.
FOXP2 is located on chromosome 7q31, and studies of other disorders with speech and language impairment, including autism, have found linkage to this region.
The SPCH1 locus has previously been linked with a severe speech and language disorder and autism, and a mutation in exon 14 of the FOXP2 gene on 7q32 has been identified in one large pedigree.
We conclude that coding-region variants in FOXP2 do not underlie the AUTS1 linkage and that the gene is unlikely to play a role in autism or more common forms of language impairment.