rs431825381
Variant summary
Our verdict is Uncertain significance. Variant got 2 ACMG points: 2P and 0B. PVS1_Moderate
The NM_000059.4(BRCA2):c.9945delA(p.Glu3316AsnfsTer2) variant causes a frameshift change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000682 in 1,614,042 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★★★).
Frequency
Consequence
NM_000059.4 frameshift
Scores
Clinical Significance
Conservation
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ACMG classification
Verdict is Uncertain_significance. Variant got 2 ACMG points.
Transcripts
RefSeq
Ensembl
Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | TSL | MANE | Protein | Appris | UniProt |
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BRCA2 | ENST00000380152.8 | c.9945delA | p.Glu3316AsnfsTer2 | frameshift_variant | Exon 27 of 27 | 5 | NM_000059.4 | ENSP00000369497.3 | ||
BRCA2 | ENST00000530893.7 | c.9576delA | p.Glu3193AsnfsTer2 | frameshift_variant | Exon 27 of 27 | 1 | ENSP00000499438.2 | |||
BRCA2 | ENST00000614259.2 | n.*2003delA | non_coding_transcript_exon_variant | Exon 26 of 26 | 2 | ENSP00000506251.1 | ||||
BRCA2 | ENST00000614259.2 | n.*2003delA | 3_prime_UTR_variant | Exon 26 of 26 | 2 | ENSP00000506251.1 |
Frequencies
GnomAD3 genomes AF: 0.0000263 AC: 4AN: 152058Hom.: 0 Cov.: 32
GnomAD3 exomes AF: 0.0000159 AC: 4AN: 251220Hom.: 0 AF XY: 0.00000736 AC XY: 1AN XY: 135782
GnomAD4 exome AF: 0.00000479 AC: 7AN: 1461866Hom.: 0 Cov.: 31 AF XY: 0.00000275 AC XY: 2AN XY: 727226
GnomAD4 genome AF: 0.0000263 AC: 4AN: 152176Hom.: 0 Cov.: 32 AF XY: 0.0000403 AC XY: 3AN XY: 74388
ClinVar
Submissions by phenotype
Breast-ovarian cancer, familial, susceptibility to, 2 Uncertain:3
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Premature stop codon is located between the recognised high-risk truncating variant c.9924C>G (p.Tyr3308Ter) and the known low-risk truncating variant c.9976A>T (p.Lys3326Ter). -
not provided Uncertain:2
Frameshift variant predicted to result in protein truncation as the last 103 amino acids are replaced with 1different amino acid; Not observed at a significant frequency in large population cohorts (Lek 2016); Also known as c.10173delA; This variant is associated with the following publications: (PMID: 25136594, 16912212) -
This variant alters the translational reading frame of the BRCA2 mRNA and is predicted to cause the premature termination of BRCA2 protein synthesis. However, this variant occurs at the end of the BRCA2 transcript and the functional and clinical significance of the residues that would be lost are unknown (PMID: 18317453 (2008), 10570174 (1999) and ENIGMA (https://enigmaconsortium.org/)). In the published literature, this variant has been reported in an individual with breast cancer (PMID: 29337092 (2018)) and in an unaffected individual (PMID: 16912212 (2006)). Published functional studies showed that this variant does not significantly affect BRCA2 protein function (PMID: 29988080 (2019)). The frequency of this variant in the general population, 0.0002 (5/24898 chromosomes (Genome Aggregation Database, http://gnomad.broadinstitute.org)), is uninformative in the assessment of its pathogenicity. Based on the available information, we are unable to determine the clinical significance of this variant. -
Hereditary cancer-predisposing syndrome Uncertain:2
This variant deletes 1 nucleotide in exon 27 of the BRCA2 gene, creating a frameshift and premature translation stop signal at the carboxyl-terminus of the protein. This truncation is not expected to trigger nonsense-mediated decay. Functional studies using BRCA2-deficient mouse embryonic stem cells reported this variant protein to have intermediate activities in complementation of cell viability, sensitivity to DNA damaging agents and homology-directed DNA repair assays with repair activity that are comparable to likely neutral control variants (PMID: 18607349, 29988080). This variant has been reported in at least three individuals affected with breast cancer (PMID: 33479248, 35264596, 36881271) and in a breast cancer case-control study in an unaffected individuals and absent in cases (PMID: 16912212). This variant has been identified in 5/282368 chromosomes in the general population by the Genome Aggregation Database (gnomAD). Loss of BRCA2 function is a known mechanism of disease (clinicalgenome.org). 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 c.9945delA variant, located in coding exon 26 of the BRCA2 gene, results from a deletion of one nucleotide at nucleotide position 9945, causing a translational frameshift with a predicted alternate stop codon (p.E3316Nfs*2). This alteration occurs at the 3' terminus of BRCA2 gene, is not expected to trigger nonsense-mediated mRNAdecay, and only impacts the last 102 amino acids of the protein. The exact functional effect of this alteration is unknown. This alteration has was reported in 1 of 674 healthy control women without breast cancer who participated in a multi-center population-based case-control study, but was not seen in any of the 1628 women with breast cancer (Malone KE et al. Cancer Res., 2006 Aug;66:8297-308). This alteration was identified in an individual diagnosed with breast cancer (Copson ER et al. Lancet Oncol, 2018 02;19:169-180). One study found this variant to be functionally sufficient in a BRCA2-null mouse embryonic stem cell complementation assay, a homology-directed repair (HDR) assay, and a cisplatin sensitivity assay (Mesman RLS et al. Genet Med, 2019 02;21:293-302). Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -
not specified Uncertain:1Benign:1
Variant summary: BRCA2 c.9945delA (p.Glu3316AsnfsX2) results in a premature termination codon. This variant is located in close proximity to another variant suggested in the literature to be a polymorphism (c.9976A>T, p.Lys3326X; classified as normal variant in our internal database). Other truncations downstream of this position have been classified by our laboratory ranging from VUS to Normal (Possibly Normal (c.9997_9998delCT, p.Leu3333fsX4); VUS (c.10024G>T, p.Glu3342X); Normal (c.10095delinsGAATTATATCT, p.Ser3366fsX4). The variant allele was found at a frequency of 1.6e-05 in 254490 control chromosomes. Additionally, it is reported in NHLBI Exome Sequencing Project in homozygous state in two individuals of African American origin; however, data from this project are included in gnomAD database and no report of homozygous occurrences exists in the specific database. The available data on variant occurrences in the general population are insufficient to allow any conclusion about variant significance. c.9945delA has been reported in the literature in individuals affected with breast cancer (Copson_2018, Walsh_2021). These reports do not provide unequivocal conclusions about association of the variant with Hereditary Breast And Ovarian Cancer Syndrome. Experimental evidence evaluating an impact on protein function did not provide strong evidence for pathogenicity of this variant (the variant showed 63% homology directed repair capacity relative to the levels observed in wild type and also, displayed cisplatin sensitivity of 61% compared to the wild type in a cell survival assay, Mesman_2018). ClinVar contains an entry for this variant (Variation ID: 96890). Based on the evidence outlined above, the variant was classified as uncertain significance. -
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BRCA2-related disorder Uncertain:1
The BRCA2 c.9945delA variant is predicted to result in a frameshift and premature protein termination (p.Glu3316Asnfs*2). This variant (also known as 9940delA, K3314fs and p.Lys3315fs) has been reported in both affected individuals with a history of breast cancer (Appendix Table 2, Copson et al. 2018. PubMed ID: 29337092; Table S3, Walsh et al. 2021. PubMed ID: 33479248). Functional studies suggest this variant does not substantially impact BRCA2 function (see Mesman. 2018. PubMed ID: 29988080). This variant is reported in 0.020% of alleles in individuals of African descent in gnomAD (http://gnomad.broadinstitute.org/variant/13-32972589-GA-G). In ClinVar, this variant is interpreted as uncertain and has been reviewed by an expert panel (https://www.ncbi.nlm.nih.gov/clinvar/variation/96890/). Taken together, the clinical significance of this variant is uncertain due to the absence of conclusive functional and genetic evidence. -
Familial cancer of breast Uncertain:1
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Hereditary breast ovarian cancer syndrome Uncertain:1
This sequence change creates a premature translational stop signal (p.Glu3316Asnfs*2) in the BRCA2 gene. While this is not anticipated to result in nonsense mediated decay, it is expected to disrupt the last 103 amino acid(s) of the BRCA2 protein. This variant is present in population databases (rs778530487, gnomAD 0.02%). This premature translational stop signal has been observed in individual(s) with breast cancer (PMID: 29337092, 33479248, 35264596, 36881271). This variant is also known as 9940delA (K3314fs) and c.9945del (p.Lys3315fs). ClinVar contains an entry for this variant (Variation ID: 96890). Algorithms developed to predict the effect of variants on gene product structure and function are not available or were not evaluated for this variant. Experimental studies have shown that this premature translational stop signal does not substantially affect BRCA2 function (PMID: 29988080). 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