rs777354703
Variant summary
Our verdict is Uncertain significance. Variant got 2 ACMG points: 2P and 0B. PP3_Moderate
The NM_001849.4(COL6A2):c.2810G>A(p.Arg937Gln) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000448 in 1,606,070 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★).
Frequency
Consequence
NM_001849.4 missense
Scores
Clinical Significance
Conservation
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ACMG classification
Verdict is Uncertain_significance. Variant got 2 ACMG points.
Transcripts
RefSeq
Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | MANE | Protein | UniProt |
---|---|---|---|---|---|---|---|---|
COL6A2 | NM_001849.4 | c.2810G>A | p.Arg937Gln | missense_variant | Exon 28 of 28 | ENST00000300527.9 | NP_001840.3 |
Ensembl
Frequencies
GnomAD3 genomes AF: 0.0000526 AC: 8AN: 152180Hom.: 0 Cov.: 34
GnomAD3 exomes AF: 0.0000461 AC: 11AN: 238568Hom.: 0 AF XY: 0.0000459 AC XY: 6AN XY: 130854
GnomAD4 exome AF: 0.0000440 AC: 64AN: 1453890Hom.: 0 Cov.: 34 AF XY: 0.0000359 AC XY: 26AN XY: 723600
GnomAD4 genome AF: 0.0000526 AC: 8AN: 152180Hom.: 0 Cov.: 34 AF XY: 0.0000942 AC XY: 7AN XY: 74346
ClinVar
Submissions by phenotype
not provided Uncertain:3
A variant of uncertain significance has been identified in the COL6A2 gene. The R937Q variant has been reported previously in an individual with Bethlem myopathy who had two other COL6A2 variants identified; however, parental testing was not completed (Stehikova et al., 2016). The R937Q variant is not observed at a significant frequency in large population cohorts (Lek et al., 2016; 1000 Genomes Consortium et al., 2015; Exome Variant Server). The R937Q variant is a semi-conservative amino acid substitution, which may impact secondary protein structure as these residues differ in some properties. This substitution occurs at a position that is conserved across species. In silico analysis is inconsistent in its predictions as to whether or not the variant is damaging to the protein structure/function. Therefore, based on the currently available information, it is unclear whether this variant is a pathogenic variant or a rare benign variant. -
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Bethlem myopathy 1A Uncertain:1
This sequence change replaces arginine, which is basic and polar, with glutamine, which is neutral and polar, at codon 937 of the COL6A2 protein (p.Arg937Gln). This variant is present in population databases (rs777354703, gnomAD 0.01%). This variant has not been reported in the literature in individuals affected with COL6A2-related conditions. ClinVar contains an entry for this variant (Variation ID: 282183). Invitae Evidence Modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) has been performed for this missense variant. However, the output from this modeling did not meet the statistical confidence thresholds required to predict the impact of this variant on COL6A2 protein function. This variant disrupts the p.Arg937 amino acid residue in COL6A2. Other variant(s) that disrupt this residue have been determined to be pathogenic (PMID: 30564623; internal data). This suggests that this residue is clinically significant, and that variants that disrupt this residue are likely to be disease-causing. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at