Description
This sequence change replaces glycine, which is neutral and non-polar, with alanine, which is neutral and non-polar, at codon 2006 of the COL7A1 protein (p.Gly2006Ala). This variant is not present in population databases (gnomAD no frequency). This missense change has been observed in individuals with autosomal dominant epidermolysis bullosa dystrophica (PMID: 10504458, 33274474). 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. 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. This variant disrupts the p.Gly2006 amino acid residue in COL7A1. Other variant(s) that disrupt this residue have been observed in individuals with COL7A1-related conditions (PMID: 9668111, 14616374), which suggests that this may be a clinically significant amino acid residue. For these reasons, this variant has been classified as Pathogenic.
# | Sample | Method | Observation |
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Origin | Affected | Number tested | Tissue | Purpose | Method | Individuals | Allele frequency | Families | Co-occurrences |
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1 | germline | unknown | not provided | not provided | not provided | | not provided | not provided | not provided | not provided |