ClinVar

Description

This sequence change replaces glycine, which is neutral and non-polar, with arginine, which is basic and polar, at codon 109 of the COL1A2 protein (p.Gly109Arg). This variant is not present in population databases (gnomAD no frequency). This missense change has been observed in individual(s) with autosomal dominant osteogenesis imperfecta (Invitae). Experimental studies and prediction algorithms are not available or were not evaluated, and the functional significance of this variant is currently unknown. This variant disrupts the triple helix domain of COL1A2. 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). In COL1A2, variants affecting these glycine residues are significantly enriched in individuals with disease (PMID: 9016532, 17078022) compared to the general population (ExAC). This variant disrupts the p.Gly109 amino acid residue in COL1A2. Other variant(s) that disrupt this residue have been observed in individuals with COL1A2-related conditions (PMID: 23692737, 27510842), which suggests that this may be a clinically significant amino acid residue. In summary, the currently available evidence indicates that the variant is pathogenic, but additional data are needed to prove that conclusively. Therefore, this variant has been classified as Likely Pathogenic.