2-214767579-C-T
Variant summary
Our verdict is Uncertain significance. The variant received 3 ACMG points: 4P and 1B. PM2PP3_ModerateBS2_Supporting
The NM_000465.4(BARD1):c.1471G>A(p.Gly491Arg) variant causes a missense change. The variant allele was found at a frequency of 0.00000342 in 1,461,752 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 (★★). Another nucleotide change resulting in the same amino acid substitution has been previously reported as Uncertain significance in ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. G491E) has been classified as Uncertain significance.
Frequency
Consequence
NM_000465.4 missense
Scores
Clinical Significance
Conservation
Publications
- breast cancerInheritance: AD Classification: DEFINITIVE Submitted by: G2P
- hereditary breast carcinomaInheritance: AD Classification: DEFINITIVE, STRONG Submitted by: Ambry Genetics, Labcorp Genetics (formerly Invitae), ClinGen
- familial ovarian cancerInheritance: AD Classification: LIMITED Submitted by: ClinGen
- hereditary nonpolyposis colon cancerInheritance: AD Classification: LIMITED Submitted by: ClinGen
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ACMG classification
Our verdict: Uncertain_significance. The variant received 3 ACMG points.
Transcripts
RefSeq
Ensembl
Frequencies
GnomAD3 genomes Cov.: 33
GnomAD2 exomes AF: 0.00000796 AC: 2AN: 251300 AF XY: 0.00000736 show subpopulations
GnomAD4 exome AF: 0.00000342 AC: 5AN: 1461752Hom.: 0 Cov.: 34 AF XY: 0.00000275 AC XY: 2AN XY: 727184 show subpopulations
Age Distribution
GnomAD4 genome Cov.: 33
ClinVar
Submissions by phenotype
Hereditary cancer-predisposing syndrome Uncertain:2
This missense variant replaces glycine with arginine at codon 491 of the BARD1 protein. Computational prediction is inconclusive regarding the impact of this variant on protein structure and function (internally defined REVEL score threshold 0.5 < inconclusive < 0.7, PMID: 27666373). To our knowledge, functional studies have not been reported for this variant. This variant has not been reported in individuals affected with hereditary cancer in the literature. This variant has been identified in 2/251300 chromosomes in the general population by the Genome Aggregation Database (gnomAD). The available evidence is insufficient to determine the role of this variant in disease conclusively. Therefore, this variant is classified as a Variant of Uncertain Significance. -
The p.G491R variant (also known as c.1471G>A), located in coding exon 6 of the BARD1 gene, results from a G to A substitution at nucleotide position 1471. The glycine at codon 491 is replaced by arginine, an amino acid with dissimilar properties. This amino acid position is highly conserved in available vertebrate species. In addition, this alteration is predicted to be deleterious by in silico analysis. Based on the available evidence, the clinical significance of this variant remains unclear. -
not provided Uncertain:1
Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; Not observed in any cases, but was observed in unaffected controls from a biliary tract cancer study (PMID: 36243179); Published functional studies demonstrate a damaging effect: reduced binding compared to wildtype (PMID: 34102105); This variant is associated with the following publications: (PMID: 18480049, 36243179, 34102105) -
Familial cancer of breast Uncertain:1
This sequence change replaces glycine, which is neutral and non-polar, with arginine, which is basic and polar, at codon 491 of the BARD1 protein (p.Gly491Arg). This variant is present in population databases (rs587782003, gnomAD 0.004%). This variant has not been reported in the literature in individuals affected with BARD1-related conditions. ClinVar contains an entry for this variant (Variation ID: 141777). An algorithm developed to predict the effect of missense changes on protein structure and function (PolyPhen-2) suggests that this variant is likely to be disruptive. Experimental studies have shown that this missense change affects BARD1 function (PMID: 34102105). RNA analysis performed to evaluate the impact of this missense change on mRNA splicing indicates it does not significantly alter splicing (internal data). 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