ClinVar

Description

Variant summary: GJB2 c.416G>A (p.Ser139Asn) results in a conservative amino acid change located in the Connexin, N-terminal domain of the encoded protein sequence. Three of five in-silico tools predict a benign effect of the variant on protein function. The variant allele was found at a frequency of 0.00029 in 251378 control chromosomes. This frequency is not significantly higher than expected for a pathogenic variant in GJB2 causing Autosomal Recessive Non-Syndromic Hearing Loss (0.00029 vs 0.025), allowing no conclusion about variant significance. The variant, c.416G>A, has been reported in the literature in multiple individuals affected with Autosomal Recessive Non-Syndromic Hearing Loss in compound heterozygous state with other pathogenic or potentially pathogenic variants (Marlin_2001, Santos_2005, Snoeckx_2005, Dodson_2011, Burke_2016, Plevova_2018). Additionally, it was found to segregate with disease in two affected siblings in a family (Santos_2005). This variant has also been found in hearing loss patients whose second mutation was not identified (Wu_2002, Azaiez_2004, Dai_2009, Bazazzadegan_2012, Bonyadi_2014). These data indicate that the variant is very likely to be associated with disease. Functional studies in HeLa cells showed defective localization and coupling (Fleishman_2006). 14 clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014 without evidence for independent evaluation, thirteen have classified as likely pathogenic/pathogenic while one has classified as benign. Based on the evidence outlined above, the variant was classified as pathogenic.