GJB3 and sensorineural hearing loss disorder: 31 In their study, two different GJB3 mutations (p.N166S and p.A194T) were identified in three unrelated families among 108 Chinese families with a single pathogenic GJB2 mutation.31 This strongly corroborated a possible digenic etiology of SNHL involving GJB2 and GJB3 in SH175-389.