13-32363178-G-C
Variant summary
The NM_000059.4(BRCA2):c.7977-1G>C variant causes a splice acceptor, intron change involving the alteration of a conserved nucleotide. The variant is predicted to lead to nonsense-mediated mRNA decay (NMD). The variant allele was found at a cumulative frequency of 0.0000031 (AC=5) in the gnomAD database across 1,612,350 control chromosomes (no homozygotes observed). The grpmax filtering allele frequency (95% CI) is 0.0000147. In-silico predictor (BayesDel (noAF)) classifies this variant as likely damaging/oncogenic. The affected nucleotide is highly conserved across species (PhyloP 100-way vertebrate score: 9.52). Variant has been reported in ClinVar as Pathogenic/Likely Pathogenic (★★★). ClinVar reports functional evidence for this variant: "SCV000073381: Studies have shown that disruption of this splice site results in skipping of exons 17-18 and skipping of exon 18, and produces a non-functional protein and/or introduces a premature termination codon (PMID:16211554, 22006311" and additional evidence is available in ClinVar.
Frequency
Consequence
NM_000059.4 splice_acceptor, intron
Scores
Clinical Significance
Conservation
Publications
- BRCA2-related cancer predispositionInheritance: AD Classification: DEFINITIVE Submitted by: ClinGen
- breast-ovarian cancer, familial, susceptibility to, 2Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), Genomics England PanelApp, Ambry Genetics
- Fanconi anemia complementation group D1Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: G2P, Labcorp Genetics (formerly Invitae), ClinGen, Ambry Genetics
- pancreatic cancer, susceptibility to, 2Inheritance: AD Classification: STRONG Submitted by: Genomics England PanelApp
- sarcomaInheritance: AD Classification: MODERATE Submitted by: Genomics England PanelApp
- hereditary breast ovarian cancer syndromeInheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
- Fanconi anemiaInheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
- medulloblastomaInheritance: AD Classification: LIMITED Submitted by: Ambry Genetics
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Classification according to ACMG Germline Pathogenicity v2019
Our verdict: Pathogenic. The variant received 25 points.
| Apply | Criterion Code & Title / Strength | Rationale / Clinical Context | |
|---|---|---|---|
| PVS1Null variant in LOF gene | Splice site frameshift, NMD predicted, LoF disease mechanism — very strong (PVS1); Splice acceptor variant predicted to cause a frameshift, triggering NMD. Loss of function is a known disease mechanism for this gene. | ||
| PS1Same amino acid change as known pathogenic | Splice site has a more-destructive ClinVar pathogenic — strong (PS1); A more pathogenic splice-site variant at the same position has been reported in ClinVar. | ||
| PS3Functional studies show damaging effect | Well-established functional study supports damaging effect (PS3); SCV000073381: Studies have shown that disruption of this splice site results in skipping of exons 17-18 and skipping of exon 18, and produces a non-functional protein and/or introduces a premature termination codon (PMID: 16211554, 22006311; internal data).; SCV000919024: The variant allele was found at a frequency of 4e-06 in 249640 control chromosomes (gnomAD). c.7977-1G>C has been reported in the literature in several individuals affected with breast, ovarian, and prostate cancer (e.g. Edwards_2003, Walsh_2011, Snape_2012, Jimenez_2013, Pritzlaff_2017, Dorling_2021). These data indicate that the variant is very likely to be associated with disease. 13 other submitters, including an expert panel (ENIGMA), have provided clinical-significance assessments for this variant in ClinVar after 2014 and all classified the variant as pathogenic.
no; SCV004848124: This variant has been shown to cause altered splicing leading to an abnormal or absent protein (Tesoriero 2005, Fraile-Bethencourt 2017).; SCV000213004: Splicing analysis has demonstrated c.7977-1G>C results in the production of a primary transcript lacking coding exon 17 (Ambry internal data; Fraile-Bethencourt E et al. PLoS Genet. 2017 Mar;13:e1006691).; SCV000683926: RNA studies have shown that this variant causes aberrant transcripts which skip exon 18, resulting in frameshifts and premature translation stop signals (PMID: 22006311, 28339459).; SCV004101453: RT-PCR and Mini-gene assays demonstrated that the variant impacts splicing by skipping of exon 18 (PMIDs: 16211554, 28339459). | ||
| PM2Absent/extremely low in population databases | Rare in gnomAD for AD/XL gene (popmax AF below threshold) — PM2 Supporting; GnomAD popmax AF = 0.0000147 — borderline rare for AD+AR gene (base 0.0001, raised to 0.000139 by highest known P/LP ClinVar AF 0.000139) — PM2 supporting. | ||
| PP5Reputable source reports pathogenic | ClinVar ≥3 stars pathogenic — very strong (PP5); ClinVar submissions overwhelmingly pathogenic (≥10 total, ≥80% P/LP, <10% B/LB) — strong (PP5, count-based); ClinVar germline classification: Pathogenic/Likely Pathogenic, 3 star(s). ClinVar submissions strongly and reliably favor pathogenicity (23/23 total P/LP). |
Variant Effect in Transcripts
Automated classification analysis was done for transcript: NM_000059.4. You can select a different transcript below to see updated classification assignments.
RefSeq Transcripts
| Sel. | Gene / Transcript | Tags | HGVSc / HGVSp | Effect | Exon rank | Protein / UniProt |
|---|---|---|---|---|---|---|
BRCA2 | MANE Select | c.7977-1G>C | splice_acceptorintron | Intron 17 of 26 | Prot: NP_000050.3 UniProt: | |
BRCA2 | c.7977-1G>C | splice_acceptorintron | Intron 17 of 26 | Prot: NP_001419006.1 UniProt: | ||
BRCA2 | c.7977-1G>C | splice_acceptorintron | Intron 17 of 26 | Prot: NP_001393649.1 UniProt: |
Ensembl Transcripts
| Sel. | Gene / Transcript | Tags | HGVSc / HGVSp | Effect | Exon rank | Protein / UniProt |
|---|---|---|---|---|---|---|
BRCA2 | TSL:5MANE Select | c.7977-1G>C | splice_acceptorintron | Intron 17 of 26 | Prot: ENSP00000369497.3 UniProt: | |
BRCA2 | TSL:1 | c.7977-1G>C | splice_acceptorintron | Intron 17 of 26 | Prot: ENSP00000439902.1 UniProt: | |
BRCA2 | TSL:1 | c.7608-1G>C | splice_acceptorintron | Intron 17 of 26 | Prot: ENSP00000499438.2 UniProt: |
Frequencies
Allele frequencies (AF), counts (AC/AN), homozygotes and coverage
| Source / population | AF | AC | Hom | AN | Coverage |
|---|---|---|---|---|---|
Global population databases 5 sources | |||||
GnomAD3 genomes | AF: 0.00000658 | AC:1 | Hom:0 | AN:152072 | Cov:32 |
GnomAD2 exomes | AF: 0.00000401 | AC:1 | AN:249640 | ||
GnomAD4 exome | AF: 0.00000274 | AC:4 | Hom:0 | AN:1460278 | Cov:31 |
GnomAD4 genome | AF: 0.00000658 | AC:1 | Hom:0 | AN:152072 | Cov:32 |
ALFA (dbGaP/dbSNP Allele Frequency Aggregator) | AF: 0.00 | AC:0 | Hom:0 | AN:36924 | |
Case/control cohorts
| Cohort | Cases | Controls | ||||
|---|---|---|---|---|---|---|
| AF | AC | AN | AF | AC | AN | |
SCHEMA | 0.00 | 0 | 48414 | 0.0000134 | 1 | 74516 |
ClinVar
Computational Scores
| Algorithm | Calibrated pred. | Score | Prediction |
|---|---|---|---|
AlphaGenome AVI | Pathogenic | 32 | |
BayesDel_addAF | Pathogenic | 0.38 | D |
BayesDel_noAF | Pathogenic | 0.31 | |
CADD | Pathogenic | 32 | |
DANN | Uncertain | 1.0 | |
Eigen | Pathogenic | 1.2 | |
Eigen_PC | Pathogenic | 1.0 | |
FATHMM_MKL | Pathogenic | 0.99 | D |
GPN-Star LLR | N/A | -10 | |
GPN-Star score | N/A | 10 | |
Mutation Taster | N/A | 0/100 | disease causing (ClinVar) |
PhyloP100 | Pathogenic | 9.5 |
Splicing Scores
| Algorithm | Calibrated pred. | Score | Prediction |
|---|---|---|---|
dbscSNV1_ADA | Pathogenic | 1.0 | |
dbscSNV1_RF | Pathogenic | 0.94 | |
DS_AL_spliceai | Pathogenic | 0.95 | Position offset: 1 |
Pangolin (max) | Pathogenic | 0.90 | |
Pangolin gain | Uncertain | 0.37 | Position offset: 22 |
Pangolin loss | Pathogenic | 0.90 | Position offset: 1 |
SpliceAI score (max) | Pathogenic | 0.95 | Details are displayed if max score is > 0.2 |
Splicevardb | N/A | 3.0 |
Find out detailed SpliceAI scores and Pangolin per-transcript scores at
MaxEntScan Visualizer can be used to analyze the impact of this mutation on the neighboring sequence.