GJB2 and hearing loss disorder: However, studies with the Brazilian population have shown that the screening of the GJB2 and GJB6 genes explains the etiology of hearing loss (HL) in only 1–24.7% of the subjects analyzed, being the c.35delG (rs80338939) mutation in GJB2 (NM_004004.5) gene, the most frequent pathogenic variant [6–9].