ClinVar

Description

For these reasons, this variant has been classified as Pathogenic. This variant disrupts the triple helix domain of COL7A1. Glycine residues within the Gly-Xaa-Yaa repeats of the triple helix domain are required for the structure and stability of fibrillar collagens (PMID: 7695699, 8218237, 19344236), and variants at these glycine residues in COL7A1 are more frequently observed in individuals with disease than in the general population (PMID: 22058051). However, the clinical significance of this observation remains uncertain since only a limited number of affected individuals have been described to date. Experimental studies have shown that this missense change affects COL7A1 function (PMID: 18450758). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is expected to disrupt COL7A1 protein function. ClinVar contains an entry for this variant (Variation ID: 1047980). This missense change has been observed in individual(s) with autosomal recessive dystrophic epidermolysis bullosa (PMID: 9326325). This variant is not present in population databases (gnomAD no frequency). This sequence change replaces glycine, which is neutral and non-polar, with glutamic acid, which is acidic and polar, at codon 2049 of the COL7A1 protein (p.Gly2049Glu).