Identification of a novel gene on chromosome 7q31 that is interrupted by atranslocation breakpoint in an autistic individual

The results of genetic linkage studies for autism have suggested that a sus ceptibility locus for the disease is located on the long arm of chromosome 7 (7q). An autistic individual carrying a translocation, t(7;13)(q31.3;q21) , with the chromosome 7 breakpoint located in the region of 7q implicated b y genetic studies was identified. A novel gene known as "RAY1" (or "FAM4A1" ) was found to be directly interrupted by the translocation breakpoint. The gene, which was found to be encoded by 16 exons with evidence of alternati ve splicing, spanned greater than or equal to 220 kb of DNA at 7q31.3. Muta tion screening of the entire coding region in a set of 27 unrelated autisti c individuals failed to identify phenotype-specific variants, suggesting th at coding region mutations are unlikely to be involved in the etiology of a utism. Apparent homologues of RAY1 have also been identified in mouse, rat, pig, chicken, fruit fly, and nematode. The human and mouse genes share sim ilar splicing patterns, and their predicted protein products are 98% identi cal.