USH2A and autosomal recessive nonsyndromic hearing loss 31: In addition, mutations in three corresponding genes (usherin USH2A[14], G protein-coupled receptor 98; GPR98[15], and deafness, autosomal recessive 31; DFNB31[16]) have been reported so far in USH2, and USH3 is caused by mutations in the clarin 1 (CLRN1) [17] gene.