In R4 family, a novel nonsense mutation caused by c.2758 C>T (p.R920X) was detected in PCDH15, which is responsible for both Usher syndrome 1F (USH1F) and deafness autosomal recessive type 23 (DFNB23) hearing loss [19]. This evidence concerns the gene PCDH15 and autosomal recessive nonsyndromic hearing loss 23.