GJB1 variants classified in ClinVar

This is a schematic of a Cx32 molecule, which consists of 4 transmembrane domains, 2 extracellular loops, 1 intracellular loop, as well as intracellular N- and C-termini. The 421 missense GJB1 variants classified by ClinVar are shown; 95 are considered “pathogenic” or “likely pathogenic,” 266 are considered “uncertain,” 17 are considered “conflicting,” and 20 are considered “benign.” The 18 benign variants that are synonymous, as well as frameshift and nonsense mutations, are not shown. In my opinion, not all of the variants have not yet been properly classified by ClinVar: there are many “uncertain” variants that are “pathogenic”/“likely pathogenic” (they have been reported in people with CMTX1) or “benign” (GJB1 variants with allele counts greater than 2 are probably too common to cause CMTX1). The approximately 300 additional, missense mutations that are not listed in ClinVar are not shown. (Contributed by Dr. Steven Scherer.)