The c.584T>C is a missense variant predicted to cause a substitution of methionine by threonine at amino acid 195 (p.Met195Thr). The highest population minor allele frequency in gnomAD v4.1.0 is 0.0022% (4/60018, CI 95%) in the Admixed American population (PM2_Supporting). The c.584T>C variant has been detected in trans with c.35delG in one individual with moderate-severe hearing loss (PMID: 19235794). The computational predictor REVEL gives a score of 0.968 which is above the threshold of 0.7, evidence that correlates with impact to GJB2 function (PP3). Another missense variant c.583G>C (p.Met195Val; ClinVar Variation ID: 22537) in the same codon has been classified as pathogenic for hearing loss by the ClinGen Hearing Loss VCEP (PM5). Analysis in Hela cells demonstrated that the CX26-p.Met195Thr protein formed a gap junction but with significantly decreased dye transfer. Additionally, electrophysiological characterization of the mutant in Xenopus oocytes resulted in a completely non-functional channel (PS3_Moderate; PMID: 23967136). In summary, this variant meets the criteria to be classified as likely pathogenic for autosomal recessive non-syndromic hearing loss based on the ACMG/AMP criteria applied, as specified by the ClinGen Hearing Loss VCEP (PM2_Supporting, PP3, PM3, PM5, PS3_Moderate; Version 2; 5/15/24).