rs397507404
Variant summary
Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PVS1PM2PP5_Very_Strong
The NM_000059.4(BRCA2):c.8488-1G>A variant causes a splice acceptor, intron change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000274 in 1,461,766 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Pathogenic (★★★).
Frequency
Consequence
NM_000059.4 splice_acceptor, intron
Scores
Clinical Significance
Conservation
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ACMG classification
Verdict is Pathogenic. Variant got 18 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.8488-1G>A | splice_acceptor_variant, intron_variant | Intron 19 of 26 | 5 | NM_000059.4 | ENSP00000369497.3 | |||
BRCA2 | ENST00000530893.7 | c.8119-1G>A | splice_acceptor_variant, intron_variant | Intron 19 of 26 | 1 | ENSP00000499438.2 | ||||
BRCA2 | ENST00000614259.2 | n.*546-1G>A | splice_acceptor_variant, intron_variant | Intron 18 of 25 | 2 | ENSP00000506251.1 |
Frequencies
GnomAD3 genomes Cov.: 32
GnomAD4 exome AF: 0.00000274 AC: 4AN: 1461766Hom.: 0 Cov.: 31 AF XY: 0.00000138 AC XY: 1AN XY: 727186
GnomAD4 genome Cov.: 32
ClinVar
Submissions by phenotype
Breast-ovarian cancer, familial, susceptibility to, 2 Pathogenic:9
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ACMG classification criteria: PVS1 very strong, PS3 supporting, PS4 moderate, PM2 moderate -
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IARC class based on posterior probability from multifactorial likelihood analysis, thresholds for class as per Plon et al. 2008 (PMID: 18951446). Class 5 based on posterior probability = 0.992712 -
not provided Pathogenic:5
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This variant disrupts a canonical splice-acceptor site and interferes with normal BRCA2 mRNA splicing (PMIDs: 22632462 (2012), 24607278 (2014)). In the published literature, the variant has been reported in individuals with Fanconi anemia (PMID: 12065746 (2002)) and with breast/ovarian cancer (PMIDs: 24607278 (2014), 30078507 (2018), 30606148 (2019)). It has not been reported in large, multi-ethnic general populations (http://gnomad.broadinstitute.org). Based on the available information, this variant is classified as pathogenic. -
PP3, PP5, PM2, PS3_moderate, PVS1_moderate -
Observed in multiple individuals with personal and/or family histories consistent with Hereditary Breast and Ovarian Cancer (PMID: 22632462, 22798144, 24607278, 24916970, 27741520, 27383479, 29673794, 30606148, 30350268); Reported in the homozygous state in an individual with Fanconi anemia that was described as mild, whose lympohoblasts exhibited modest MMC sensitivity; as well as a second individual with non-obstructive azoospermia (PMID: 12065746, 35535697); Published functional studies are inconclusive: marginal sensitivity to PARP inhibitor and other DNA damaging agents and wild type levels of RAD51 foci formation (PMID: 25583207); Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports a deleterious effect on splicing; Also known as 8716-1G>A; This variant is associated with the following publications: (PMID: 24916970, 24301060, 28726806, 29446198, 26247049, 29907814, 27383479, 26834852, 25382762, 24259538, 28332257, 16115142, 25447315, 27741520, 15645491, 22798144, 19464302, 29673794, 25525159, 22632462, 24607278, 29625052, 26580448, 30606148, 30350268, 30078507, 28111427, 29790872, 31131967, 33008098, 31447099, 33397043, 31589614, 28888541, 32986223, 34235180, 34413315, 35535697, 32719484, 34645131, 35264596, 36988593, 36451132, 34326862, 33309985, 33087929, 35534704, 12065746, 36881271, 36721989, 37118955, 38671360, 25583207) -
Hereditary breast ovarian cancer syndrome Pathogenic:5
Variant summary: BRCA2 c.8488-1G>A is located in a canonical splice-site and is predicted to affect mRNA splicing resulting in a significantly altered protein due to either exon skipping, shortening, or inclusion of intronic material. Several computational tools predict a significant impact on normal splicing: Two predict that the variant abolishes a 3' acceptor site. Several publications report experimental evidence that this variant affects mRNA splicing (e.g. Acedo_2012, Santos_2014). The variant was absent in 251414 control chromosomes. c.8488-1G>A has been reported in the literature in individuals affected with Hereditary Breast And Ovarian Cancer Syndrome (e.g. Acedo_2012, Kim_2012, Peixoto_2014, Fernandes_2016) and Fanconi anemia (e.g. Howlett_2002). These data indicate that the variant is likely to be associated with disease.Several publications report experimental evidence evaluating an impact on protein function, indicating that the variant impairs protein function (e.g. Howlett_2002, Godthelp_2006). 13 other clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014 without evidence for independent evaluation. All laboratories classified the variant as pathogenic/likely pathogenic. Based on the evidence outlined above, the variant was classified as pathogenic. -
This sequence change affects an acceptor splice site in intron 19 of the BRCA2 gene. It is expected to disrupt RNA splicing. Variants that disrupt the donor or acceptor splice site typically lead to a loss of protein function (PMID: 16199547), and loss-of-function variants in BRCA2 are known to be pathogenic (PMID: 20104584). This variant is not present in population databases (gnomAD no frequency). Disruption of this splice site has been observed in individual(s) with breast cancer, autosomal recessive Fanconi anemia (PMID: 22632462, 24301060, 24607278, 27741520, 31331294). This variant is also known as Ex19-1G>A, IVS19-1G>A. ClinVar contains an entry for this variant (Variation ID: 38164). Based on a multifactorial likelihood algorithm using genetic, in silico, and/or statistical data, this variant has been determined to have a high probability of being pathogenic (PMID: 12065746). Studies have shown that this variant is associated with altered splicing resulting in multiple RNA products ( PMID: 22632462, 24607278, 25382762; internal data). For these reasons, this variant has been classified as Pathogenic. -
The c.8488-1G>A variant in BRCA2 has been reported in the heterozygous state in at least 8 individuals with BRCA2-related cancers, and in the homozygous state in 1 individual with Fanconi anemia (Acedo 2012 PMID: 22632462, Santos 2014 PMID: 24607278, Park 2017 PMID: 28111427, Li 2018 PMID: 30078507 , Palmero 2018 PMID: 29907814, Cotrim 2019 PMID: 30606148). This variant has also been reported by other clinical laboratories in ClinVar (Variation ID: 38164) and was absent from large population studies. This variant occurs within the canonical splice site (+/- 1,2) and is predicted to cause altered splicing leading to an abnormal or absent protein. Sequencing of patient RNA confirms that this variant leads to abnormal splicing (Howlett 2002 PMID: 12065746, Acedo 2012 PMID: 22632462, Santos 2014 PMID: 24607278). In summary, this variant meets criteria to be classified as pathogenic for autosomal dominant hereditary breast and ovarian cancer (HBOC). ACMG/AMP Criteria applied: PVS1, PM2_Supporting, PS4_Moderate. -
The c.8488-1G>A variant in the BRCA2 gene is located at the canonical acceptor splice site of intron 19. It is predicted to result in acceptor loss (SpliceAI delta score: 0.92) and aberrant splicing and disrupted protein product. The variant has been reported in multiple individuals with breast/ovarian/prostate cancer (PMID: 35264596, 37118955, 30350268, 22798144, 34235180). This variant has also been reported in homozygosity in an individual affected with Fanconi anemia (PMID: 12065746). Experimental RNA analysis in patient lymphocytes and minigene assay have shown that this variant may cause aberrant transcripts (PMID: 22632462, 12065746, 24607278). Loss-of-function variants of BRCA2 are known to be pathogenic (PMID: 8988179, 11897832, 29446198). The variant is reported in ClinVar as pathogenic (ID:38164) and reviewed by the expert panel. The variant is absent in the general population database (gnomAD). Therefore, the c.8488-1G>A variant in the BRCA2 gene has been classified as pathogenic. -
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Hereditary cancer-predisposing syndrome Pathogenic:2
This variant causes a G>A nucleotide substitution at the canonical -1 position of intron 19 splice acceptor site of the BRCA2 gene. This variant is also known as IVS19-1G>A in the literature. RNA studies have shown that this variant results in several different abnormally spliced transcripts, including a transcript missing 12 nucleotides of exon 20, a transcript that retains intron 19, and another transcript with exon 20 skipping (PMID: 12065746, 22632462, 24607278, 25382762; ClinVar SCV000278235.5). Functional studies have shown that the mutant protein results in a decreased number of cells with RAD51 foci and reduced focus size, confers a moderate defect in homologous recombination, and disrupts replication fork protection function (PMID: 32354836). This variant has been observed in over ten individuals affected with breast and/or ovarian cancer (PMID: 22632462, 22798144, 24916970, 27741520, 33008098; Chheda 2020, DOI: 10.4103/CRST.CRST_1; Color data) and in an individual affected with colorectal cancer with family history of breast cancer (PMID: 33309985). This variant has also been reported in a homozygous individual affected with a mild form of Fanconi anemia (PMID: 12065746), and cells derived from this individual showed a modest sensitivity to a DNA damaging agent, suggesting that this variant may be hypomorphic in some individuals. This variant has not been identified in the general population by the Genome Aggregation Database (gnomAD). Loss of BRCA2 function is a known mechanism of disease (clinicalgenome.org). Based on the available evidence, this variant is classified as Pathogenic. -
The c.8488-1G>A intronic pathogenic mutation results from a G to A substitution one nucleotide upstream from coding exon 19 of the BRCA2 gene. This mutation was previously reported in a homozygous state in one Fanconi anemia patient of subtype D1 with a family history of consanguinity (Howlett NG et al. Science. 2002 Jul;26:297(5581):606-9). Results from various functional splicing assays performed on this alteration demonstrated that this mutation results in three to five different abnormally spliced transcripts, which includes production of an abnormal transcript that loses 12 nucleotides of exon 20, a transcript that retains intron 19, and another transcript with exon 20 skipping (Acedo et al. Breast Cancer Res. 2012 May; 25:14(3):R87; Santos C et al. J. Mol. Diagn. 2014 May;16(3):324-34; Acedo et al Hum. Mutat. 2015 Feb;36(2):210-21; Ambry internal data). This variant is considered to be rare based on population cohorts in the Genome Aggregation Database (gnomAD). In addition to the clinical data presented in the literature, alterations that disrupt the canonical splice site are expected to cause aberrant splicing, resulting in an abnormal protein or a transcript that is subject to nonsense-mediated mRNA decay. As such, this alteration is classified as a disease-causing mutation. However, because this variant is identified in one or more patients with Fanconi Anemia it may be hypomorphic and thus, carriers of this variant and their families may present with reduced risks, and not with the typical clinical characteristics of a high-risk pathogenic BRCA2 alteration. As risk estimates are unknown at this time, clinical correlation is advised. -
Medulloblastoma;C0346153:Familial cancer of breast;C0376358:Malignant tumor of prostate;C1838457:Fanconi anemia complementation group D1;C2675520:Breast-ovarian cancer, familial, susceptibility to, 2;C2751641:Glioma susceptibility 3;C3150546:Pancreatic cancer, susceptibility to, 2;CN033288:Wilms tumor 1 Pathogenic:1
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BRCA2-related cancer predisposition Pathogenic:1
This variant causes a G>A nucleotide substitution at the canonical -1 position of intron 19 splice acceptor site of the BRCA2 gene. This variant is also known as IVS19-1G>A in the literature. RNA studies have shown that this variant results in several different abnormally spliced transcripts, including a transcript missing 12 nucleotides of exon 20, a transcript that retains intron 19, and another transcript with exon 20 skipping (PMID: 12065746, 22632462, 24607278, 25382762; ClinVar SCV000278235.5). Functional studies have shown that the mutant protein results in a decreased number of cells with RAD51 foci and reduced focus size, confers a moderate defect in homologous recombination, and disrupts replication fork protection function (PMID: 32354836). This variant has been observed in over ten individuals affected with breast and/or ovarian cancer (PMID: 22632462, 22798144, 24916970, 27741520, 33008098; Chheda 2020, DOI: 10.4103/CRST.CRST_1; Color data) and in an individual affected with colorectal cancer with family history of breast cancer (PMID: 33309985). This variant has also been reported in a homozygous individual affected with a mild form of Fanconi anemia (PMID: 12065746), and cells derived from this individual showed a modest sensitivity to a DNA damaging agent, suggesting that this variant may be hypomorphic in some individuals. This variant has not been identified in the general population by the Genome Aggregation Database (gnomAD). Loss of BRCA2 function is a known mechanism of disease (clinicalgenome.org). Based on the available evidence, this variant is classified as Pathogenic. -
Fanconi anemia complementation group D1 Pathogenic:1
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BRCA2-related disorder Pathogenic:1
The c.8488-1G>A variant is located in a canonical splice-site, and it is predicted to alter gene function due to either exon skipping or nonsense-mediate decay – NMD, and the variant is present in a relevant exon to the transcript - PVS1. This sequence change has been observed in affected individual(s) and ClinVar contains an entry for this variant (ClinVar ID: 38164; PMID: 22632462; PMID: 24607278; PMID: 27741520; PMID: 25382762; PMID: 22632462) - PS4. This variant is not present in population databases (rs397507404- gnomAD; ABraOM no frequency - http://abraom.ib.usp.br) - PM2. In summary, the currently available evidence indicates that the variant is pathogenic -
Gastric cancer Pathogenic:1
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Familial cancer of breast Pathogenic:1
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Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at