LOCALIZATION OF THE USHER-SYNDROME TYPE ID GENE (USH1D) TO CHROMOSOME-10

The Usher syndromes (USH) are a group of autosomal recessive diseases characterized by progressive pigmentary retinopathy and sensorineural hearing loss, Five USH genes have been mapped and at least one additio nal gene is known to exist, By homozygosity mapping in a consanguineou s family, a sixth USH gene has been localized, Clinical findings in th e four affected children are consistent with established diagnostic cr iteria for Ush1, Linkage to known USH loci was excluded, and using two genomic DNA pools, one from the affected children and the other from the parents, 161 polymorphic markers evenly spaced across the autosoma l human genome were screened, The location of the Ush1 D gene was defi ned by the only region showing homozygosity by descent in the affected siblings, a15 cM interval on chromosome 10q bounded by D10S529 and D1 0S573.