Deletion of 7q31.1 supports involvement of FOXP2 in language impairment: clinical report and review

Abstract

We report on a young male with moderate mental retardation, dysmorphic features, and language delay who is deleted for 7q31.1-7q31.31. His full karyotype is 46,XY,der(7)del(7)(q31.1q31.31)ins(10;7)(q24.3;q31.1q31.31)mat. This child had language impairment, including developmental verbal dyspraxia, but did not meet criteria for autism according to standardized ADOS testing. Our patient's deletion, which is the smallest reported deletion including FOXP2, adds to the body of evidence that supports the role of FOXP2 in speech and language impairment, but not in autism. A reported association between autism and deletions of WNT2, a gene also deleted in our patient, is likewise not supported by our case. Previously, fine mapping with microsatellites markers within in a large three-generation family, in which half the members had severe specific language impairment, aided the localization of the SPCH1 locus to 7q31 within markers D7S2459 (107.1 Mb) and D7S643 (120.5 Mb). Additionally, chromosome rearrangement of 7q31 and mutational analyses have supported the growing evidence that FOXP2, a gene within the SPCH1 region, is involved with speech and language development. It is unclear however whether the AUTS1 (autistic spectrum 1) locus, highly linked to 7q31, overlaps with the SPCH1 and FOXP2.