2-214767611-A-G
Variant summary
Our verdict is Uncertain significance. The variant received 4 ACMG points: 4P and 0B. PP3_Strong
The NM_000465.4(BARD1):c.1439T>C(p.Leu480Ser) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000372 in 1,613,978 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 variant affecting the same amino acid position, but resulting in a different missense (i.e. L480F) 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 4 ACMG points.
Transcripts
RefSeq
| Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | MANE | Protein | UniProt |
|---|---|---|---|---|---|---|---|---|
| BARD1 | NM_000465.4 | c.1439T>C | p.Leu480Ser | missense_variant | Exon 6 of 11 | ENST00000260947.9 | NP_000456.2 |
Ensembl
| Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | TSL | MANE | Protein | Appris | UniProt |
|---|---|---|---|---|---|---|---|---|---|---|
| BARD1 | ENST00000260947.9 | c.1439T>C | p.Leu480Ser | missense_variant | Exon 6 of 11 | 1 | NM_000465.4 | ENSP00000260947.4 |
Frequencies
GnomAD3 genomes AF: 0.0000197 AC: 3AN: 152208Hom.: 0 Cov.: 33 show subpopulations
GnomAD2 exomes AF: 0.0000119 AC: 3AN: 251316 AF XY: 0.00000736 show subpopulations
GnomAD4 exome AF: 0.00000205 AC: 3AN: 1461770Hom.: 0 Cov.: 34 AF XY: 0.00000138 AC XY: 1AN XY: 727188 show subpopulations
Age Distribution
GnomAD4 genome AF: 0.0000197 AC: 3AN: 152208Hom.: 0 Cov.: 33 AF XY: 0.0000134 AC XY: 1AN XY: 74362 show subpopulations
Age Distribution
ClinVar
Submissions by phenotype
not provided Uncertain:2
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; Published functional studies demonstrate significantly reduced homology-directed repair (HDR) activity compared to wildtype (PMID: 30925164); This variant is associated with the following publications: (PMID: 23056176, 30804502, 31871109, 30925164, 18480049, 37502949)
The BARD1 c.1439T>C (p.Leu480Ser) variant has been described as a variant of uncertain significance in a breast cancer case-control study (PMID: 31871109 (2019)), and shown to have deleterious effect on BARD1 DNA damage repair activity (PMID: 30925164 (2019)). The frequency of this variant in the general population, 0.0002 (5/24970 chromosomes in African/African-American subpopulation (Genome Aggregation Database, http://gnomad.broadinstitute.org)), is higher than would generally be expected for pathogenic variants in this gene. Analysis of this variant using bioinformatics tools for the prediction of the effect of amino acid changes on protein structure and function yielded predictions that this variant is damaging. Based on the available information, we are unable to determine the clinical significance of this variant.
Familial cancer of breast Uncertain:2
This sequence change replaces leucine, which is neutral and non-polar, with serine, which is neutral and polar, at codon 480 of the BARD1 protein (p.Leu480Ser). This variant is present in population databases (rs149839922, gnomAD 0.02%). 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: 186616). 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: 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.
Hereditary cancer-predisposing syndrome Uncertain:2
This missense variant replaces leucine with serine at codon 480 of the BARD1 protein. Computational prediction suggests that this variant may have deleterious impact on protein structure and function (internally defined REVEL score threshold >= 0.7, PMID: 27666373). A functional study has shown the mutant protein to exhibit significantly reduced homology-directed repair activity (PMID: 30925164). This variant has been reported in an individual affected with breast cancer (PMID: 31871109). This variant has been identified in 5/282726 chromosomes in the general population by the Genome Aggregation Database (gnomAD). All five of these alleles were observed in the African population in the non-cancer cohort (5/23616). 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.L480S variant (also known as c.1439T>C), located in coding exon 6 of the BARD1 gene, results from a T to C substitution at nucleotide position 1439. The leucine at codon 480 is replaced by serine, an amino acid with dissimilar properties. In a homology-directed repair (HDR) assay, this alteration showed HDR activity below the cutoff for proficiency (Adamovich AI et al. PLoS Genet. 2019 03;15(3):e1008049). 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.
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at