Forty-two unrelated individuals and two siblings (12-0878, 12-0880) with Usher syndrome were screened for mutations in the Usher genes CDH23, CLRN1, DFNB31, GPR98, MYO7A, PCDH15, USH1C, USH1G, and USH2A. Biallelic mutations could be identified in 35 individuals and monoallelic mutations in eight individuals. This evidence concerns the gene PCDH15 and Usher syndrome.