CDH23 and Usher syndrome type 1: The patients, who carried compound heterozygous mutations in CDH23 (NT-1-1, NT-2-1, and NT-3-1) and MYO7A (NT-5-1), two genes associated with both nonsyndromic deafness and Usher syndrome type 1, did not show any degenerative symptoms of retinitis pigmentosa.