SLC26A4 and deafness: Considering these two biallelic mutations shared one common mutant allele (IVS7-2A>G) and their other mutant alleles were both located at the same codon (codon 723) in the coding region of carboxyl terminus of pendrin, it was presumed that the genotype of their other mutant allele (c.2168A>G or c.2167C>G) could lead to a different conserved amino acid change (p.H723R or p.H723D), but both cause a deleterious impact on the protein function of pendrin, and eventually result in pathogenicity with deafness phenotypes.