2-214780858-C-T
Variant summary
Our verdict is Benign. The variant received -8 ACMG points: 0P and 8B. BP4_StrongBS2
The NM_000465.4(BARD1):c.1016G>A(p.Ser339Asn) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000167 in 1,614,104 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 16/22 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. S339T) has been classified as Likely benign.
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: Benign. The variant received -8 ACMG points.
Transcripts
RefSeq
Ensembl
Frequencies
GnomAD3 genomes AF: 0.0000131 AC: 2AN: 152172Hom.: 0 Cov.: 32 show subpopulations
GnomAD2 exomes AF: 0.0000119 AC: 3AN: 251180 AF XY: 0.0000147 show subpopulations
GnomAD4 exome AF: 0.0000171 AC: 25AN: 1461814Hom.: 0 Cov.: 34 AF XY: 0.0000193 AC XY: 14AN XY: 727200 show subpopulations
Age Distribution
GnomAD4 genome AF: 0.0000131 AC: 2AN: 152290Hom.: 0 Cov.: 32 AF XY: 0.0000134 AC XY: 1AN XY: 74460 show subpopulations
ClinVar
Submissions by phenotype
not provided Uncertain:3
Published functional studies suggest no damaging effect: HDR activity was slightly less than, yet comparable to, wildtype (PMID: 30925164); Observed in individuals with breast cancer (PMID: 30925164, 31371347); Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis suggests that this missense variant does not alter protein structure/function; This variant is associated with the following publications: (PMID: 31371347, 27363283, 33471991, 30925164) -
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Familial cancer of breast Uncertain:3
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This sequence change replaces serine, which is neutral and polar, with asparagine, which is neutral and polar, at codon 339 of the BARD1 protein (p.Ser339Asn). This variant is present in population databases (rs201261729, gnomAD 0.002%). This missense change has been observed in individual(s) with breast cancer (PMID: 31371347). ClinVar contains an entry for this variant (Variation ID: 182043). An algorithm developed to predict the effect of missense changes on protein structure and function outputs the following: PolyPhen-2: "Benign". The asparagine amino acid residue is found in multiple mammalian species, which suggests that this missense change does not adversely affect protein function. Experimental studies have shown that this missense change does not substantially affect BARD1 function (PMID: 30925164). 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. -
The BARD1 c.1016G>A (p.Ser339Asn) missense change has a maximum subpopulation frequency of 0.003% in gnomAD v2.1.1 (https://gnomad.broadinstitute.org/). The in silico tool REVEL predicts a benign effect on protein function and a homology-directed repair assay supports that this variant is functional (PMID: 30925164). This variant has been reported in an individual with breast cancer (PMID: 31371347). In summary, the evidence currently available is insufficient to determine the clinical significance of this variant. It has therefore been classified as of uncertain significance. -
Hereditary cancer-predisposing syndrome Uncertain:1Benign:2
This alteration is classified as likely benign based on a combination of the following: seen in unaffected individuals, population frequency, intact protein function, lack of segregation with disease, co-occurrence, RNA analysis, in silico models, amino acid conservation, lack of disease association in case-control studies, and/or the mechanism of disease or impacted region is inconsistent with a known cause of pathogenicity. -
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not specified Uncertain:2
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Variant summary: BARD1 c.1016G>A (p.Ser339Asn) results in a conservative amino acid change in the encoded protein sequence. Five of five in-silico tools predict a benign effect of the variant on protein function. The variant allele was found at a frequency of 1.2e-05 in 251180 control chromosomes. The available data on variant occurrences in the general population are insufficient to allow any conclusion about variant significance. c.1016G>A has been reported in the literature in an individual affected with breast cancer without strong evidence for causality (Toh_2019). This report does not provide unequivocal conclusions about association of the variant with Hereditary Breast And Ovarian Cancer Syndrome. At least one publication reports experimental evidence evaluating an impact on protein function. These results showed similar HDR activity compared to wild-type (Adamovich_2019). Six clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014 without evidence for independent evaluation. Five submitters classified the variant as VUS while one classified as likely benign. Based on the evidence outlined above, the variant was classified as uncertain significance. -
Breast and/or ovarian cancer Uncertain:1
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BARD1-related cancer predisposition Uncertain:1
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Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at