13-32329440-C-G

Variant names:

• chr13-32329440-C-G
• rs568027879
• NM_000059.4:c.632-3C>G

Variant summary

Our verdict is Likely pathogenic. Variant got 6 ACMG points: 6P and 0B. PVS1_Moderate PM3 PP4_Moderate

This summary comes from the ClinGen Evidence Repository: The c.632-3C>G variant is an intronic variant occurring in intron 7 of the BRCA2 gene. This variant is present in gnomAD v2.1 (exomes only, non-cancer subset) or gnomAD v3.1 (non-cancer subset) but is below the ENIGMA BRCA1/2 VCEP threshold >0.00002 for BS1_Supporting (PM2_Supporting, BS1, and BA1 are not met). This variant is reported to result in aberrant mRNA splicing. RT-PCR and Mini-gene assays demonstrated that the variant impacts splicing by creating a new acceptor splice site, resulting in retention of 2bp from intron 7, which leads to a frameshift and generates a premature stop codon (PMIDs: 30883759, 32123317, 22505045). Reduced expression of aberrant transcript reported by one assay suggesting potential incomplete expression of the aberrant transcript (Ambry internal contributor). Appropriate code strength determined by comparison of results to PVS1 decision tree PVS1 (RNA) was downgraded to PVS1_Moderate (RNA). This variant has been detected in 2 siblings with phenotype consistent with BRCA2-Fanconi Anemia (FA). At least two clinical features of FA (physical features, pathology findings and cancer diagnosis ≤5yr) and confirmed chromosome breakage, are seen in these individuals. Both siblings were homozygous for the variant. Total points equated to 2 (PM3 met; PMID:25381700). Multifactorial likelihood ratio analysis using clinically calibrated data produced a combined LR for this variant of 12.477 (based on Pathology LR=1.07; Co-occurrence LR=1.0498; Family History LR=11.107), within the thresholds for Moderate evidence towards pathogenicity (LR >4.3 & ≤18.7) (PP4_Moderate met; PMID:31131967, 31853058). In summary, this variant meets the criteria to be classified as a Likely pathogenic variant for BRCA2-related cancer predisposition based on the ACMG/AMP criteria applied as specified by the ENIGMA BRCA1/2 VCEP (PVS1_Moderate (RNA), PM3, PP4_Moderate). LINK:https://erepo.genome.network/evrepo/ui/classification/CA348611/MONDO:0012933/097

• Frequency:
  • Genomes: 𝑓 0.000013 (0 hom., cov: 32)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: BRCA2 NM_000059.4 splice_region, intron
• Scores: Splicing: ADA: 0.9999
• Clinical Significance: Likely pathogenic reviewed by expert panel P:9 U:2
• Conservation: PhyloP100: -0.0370

Genes affected

BRCA2 (HGNC:1101): (BRCA2 DNA repair associated) Inherited mutations in BRCA1 and this gene, BRCA2, confer increased lifetime risk of developing breast or ovarian cancer. Both BRCA1 and BRCA2 are involved in maintenance of genome stability, specifically the homologous recombination pathway for double-strand DNA repair. The largest exon in both genes is exon 11, which harbors the most important and frequent mutations in breast cancer patients. The BRCA2 gene was found on chromosome 13q12.3 in human. The BRCA2 protein contains several copies of a 70 aa motif called the BRC motif, and these motifs mediate binding to the RAD51 recombinase which functions in DNA repair. BRCA2 is considered a tumor suppressor gene, as tumors with BRCA2 mutations generally exhibit loss of heterozygosity (LOH) of the wild-type allele. [provided by RefSeq, May 2020]

ACMG classification

Verdict is Likely_pathogenic. Variant got 6 ACMG points.

• PVS1: For more information check the summary or visit ClinGen Evidence Repository.
• PM3: For more information check the summary or visit ClinGen Evidence Repository.
• PP4: For more information check the summary or visit ClinGen Evidence Repository.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
BRCA2	NM_000059.4	c.632-3C>G		splice_region_variant, intron_variant	Intron 7 of 26	ENST00000380152.8	NP_000050.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
BRCA2	ENST00000380152.8	c.632-3C>G		splice_region_variant, intron_variant	Intron 7 of 26	5	NM_000059.4	ENSP00000369497.3
BRCA2	ENST00000530893.7	c.263-3C>G		splice_region_variant, intron_variant	Intron 7 of 26	1		ENSP00000499438.2
BRCA2	ENST00000614259.2	n.632-3C>G		splice_region_variant, intron_variant	Intron 6 of 25	2		ENSP00000506251.1

Frequencies

GnomAD3 genomes AF: 0.0000131 AC: 2 AN: 152154 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.0000482

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.00

Gnomad OTH AF: 0.00

GnomAD3 exomes AF: 0.00000411 AC: 1 AN: 243142 Hom.: 0 AF XY: 0.00 AC XY: 0 AN XY: 131370

Gnomad AFR exome AF: 0.0000668

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000139 AC: 2 AN: 1438228 Hom.: 0 Cov.: 27 AF XY: 0.00 AC XY: 0 AN XY: 716226

Gnomad4 AFR exome AF: 0.0000607

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome AF: 0.0000131 AC: 2 AN: 152272 Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0 AN XY: 74450

Gnomad4 AFR AF: 0.0000481

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.00

Gnomad4 OTH AF: 0.00

Bravo AF: 0.00000378

ClinVar

Significance: Likely pathogenic

Submissions summary: Pathogenic:9 Uncertain:2

Revision: reviewed by expert panel

Submissions by phenotype

Hereditary cancer-predisposing syndrome Pathogenic:2 Uncertain:1

May 19, 2020

Color Diagnostics, LLC DBA Color Health

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant causes a C to G nucleotide substitution at the -3 position of intron 7 of the BRCA2 gene. Splice site prediction tools suggest that this variant may have a significant impact on RNA splicing. Functional RNA studies have shown that this variant causes the use of an alternative splice acceptor site 2-nucleotide upstream of the reference acceptor site, creating premature translation stop signal in the RNA transcripts (PMID: 22505045, 30883759). The aberrant transcripts are expected to result in an absent or non-functional protein product. This variant has been reported in individuals affected with breast and/or ovarian cancer (PMID: 22505045, Color internal data). In addition, a multifactorial likelihood model using health history and tumor pathology data has suggested this variant have a high probability of being pathogenic (PMID: 31131967). This variant has been identified in 1/243142 chromosomes 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 Likely Pathogenic. -

Sep 11, 2021

Sema4, Sema4

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: curation

- -

Nov 09, 2023

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The c.632-3C>G intronic variant results from a C to G substitution 3 nucleotides upstream from coding exon 7 in the BRCA2 gene. This nucleotide position is well conserved in available vertebrate species. In silico splice site analysis predicts that this alteration will weaken the native splice acceptor site and will result in the creation or strengthening of a novel splice acceptor site. This alteration results in use of this novel cryptic acceptor site two nucleotides upstream of the native site resulting in a frameshifting transcript (Ambry internal data; Houdayer C et al. Hum. Mutat. 2012 Aug;33(8):1228-38; Fraile-Bethencourt E et al. J. Pathol., 2019 08;248:409-420). In addition, this alteration has been shown to express an in-frame transcript, known as 6q39_8 in the literature (Ambry internal data). This transcript has been shown to be able to perform homology directed repair in protein functional studies at a near wild-type level (Mesman, RLS et al. Genet Med 2020 08;22(8):1355-1365). This alteration was identified as homozygous in a fetus with features consistent with Fanconi anemia (Malric, A et al. Pediatr Blood Cancer 2015 Mar;62(3):463-70). Since supporting evidence is conflicting at this time, the clinical significance of this alteration remains unclear. -

not provided Pathogenic:2

Jul 01, 2022

CeGaT Center for Human Genetics Tuebingen

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

BRCA2: PVS1, PM2, PS3:Supporting -

Jul 28, 2023

GeneDx

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Non-canonical splice site variant demonstrated to result in loss-of-function (Houdayer et al., 2012; Fraile-Bethencourt et al., 2019); Multifactorial likelihood analysis suggests this variant is pathogenic (Parsons et al., 2019); Not observed at significant frequency in large population cohorts (gnomAD); Also known as 860-3C>G; This variant is associated with the following publications: (PMID: 26913838, 22505045, 29750258, 25416802, 32123317, 33466630, 30883759, 33646313, 25381700, 31131967) -

Hereditary breast ovarian cancer syndrome Pathogenic:2

Feb 17, 2025

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Variant summary: BRCA2 c.632-3C>G, also reported as IVS07-3C>G(c.630dupAG) (intron7), alters a non-conserved nucleotide located close to a canonical splice site and therefore could affect mRNA splicing, leading to a significantly altered protein sequence. Several computational tools predict a significant impact on normal splicing: Three predict the variant creates a 3' acceptor site. Three predict the variant abolishes a 3' acceptor site. One predicts the variant weakens a 3' acceptor site. At least one publication reports experimental evidence that this variant affects mRNA splicing. In vitro minigene assays determined there are 2 predicted impacts on RNA splicing; the first inserts 2 nucleotides immediately upstream of exon 8 (r.631_632ins632-1_632-2), resulting in p.Val211Glufs*18, and the second results in the skipping of exons 6_7 and insertion of 2 nucleotides upstream of exon 8 (r.478_631delins632-1_632-2), resulting in p.Gly173Lysfs*2. The aberrant transcripts comprised approximately 75% and 25% of the minigene transcript pool, respectively (example, Fraile-Bethencourt_2019) and no remaining wild type transcript was reported. In vivo RNA analysis (internal, Labcorp Genetics (formerly Invitae)) corroborated the r.631_632ins632-2_632-1 impact, which is predicted to result in nonsense mediated decay. The variant allele was found at a frequency of 4.1e-06 in 243142 control chromosomes. c.632-3C>G has been reported in the homozygous or presumed compound heterozygous state in the literature in at least 2 individuals affected with autosomal recessive Fanconi anemia (example, Malric_2015, Radulovic_2023). Further, it has also been reported in the heterozygous state in individual(s) with clinical features of Hereditary Breast and Ovarian Cancer (example, George_2021, Vasconcelos_2021). These data indicate that the variant may be associated with disease. The following publications have been ascertained in the context of this evaluation (PMID: 30883759, 33646313, 22505045, 25381700, 36721989, 33466630, 32123317). ClinVar contains an entry for this variant (Variation ID: 219896). Based on the evidence outlined above, the variant was classified as likely pathogenic. -

Nov 11, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change falls in intron 7 of the BRCA2 gene. It does not directly change the encoded amino acid sequence of the BRCA2 protein. RNA analysis indicates that this variant induces altered splicing and may result in an absent or altered protein product. This variant is present in population databases (rs568027879, gnomAD 0.007%). This variant has been observed in individual(s) with a personal and/or family history of breast and/or ovarian cancer (PMID: 22505045, 33466630, 33646313). ClinVar contains an entry for this variant (Variation ID: 219896). 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: 31131967). Variants that disrupt the consensus splice site are a relatively common cause of aberrant splicing (PMID: 17576681, 9536098). Studies have shown that this variant results in introduction of a cryptic splice acceptor site, and produces a non-functional protein and/or introduces a premature termination codon (PMID: 22505045, 30883759, 32123317; internal data). For these reasons, this variant has been classified as Pathogenic. -

Breast-ovarian cancer, familial, susceptibility to, 2 Pathogenic:1

Dec 06, 2011

Sharing Clinical Reports Project (SCRP)

Significance: Likely pathogenic

Review Status: no assertion criteria provided

Collection Method: clinical testing

- -

BRCA2-related cancer predisposition Pathogenic:1

Jun 11, 2024

ClinGen ENIGMA BRCA1 and BRCA2 Variant Curation Expert Panel, ClinGen

Significance: Likely pathogenic

Review Status: reviewed by expert panel

Collection Method: curation

The c.632-3C>G variant is an intronic variant occurring in intron 7 of the BRCA2 gene. This variant is present in gnomAD v2.1 (exomes only, non-cancer subset) or gnomAD v3.1 (non-cancer subset) but is below the ENIGMA BRCA1/2 VCEP threshold >0.00002 for BS1_Supporting (PM2_Supporting, BS1, and BA1 are not met). This variant is reported to result in aberrant mRNA splicing. RT-PCR and Mini-gene assays demonstrated that the variant impacts splicing by creating a new acceptor splice site, resulting in retention of 2bp from intron 7, which leads to a frameshift and generates a premature stop codon (PMIDs: 30883759, 32123317, 22505045). Reduced expression of aberrant transcript reported by one assay suggesting potential incomplete expression of the aberrant transcript (Ambry internal contributor). Appropriate code strength determined by comparison of results to PVS1 decision tree PVS1 (RNA) was downgraded to PVS1_Moderate (RNA). This variant has been detected in 2 siblings with phenotype consistent with BRCA2-Fanconi Anemia (FA). At least two clinical features of FA (physical features, pathology findings and cancer diagnosis <=5yr) and confirmed chromosome breakage, are seen in these individuals. Both siblings were homozygous for the variant. Total points equated to 2 (PM3 met; PMID: 25381700). Multifactorial likelihood ratio analysis using clinically calibrated data produced a combined LR for this variant of 12.477 (based on Pathology LR=1.07; Co-occurrence LR=1.0498; Family History LR=11.107), within the thresholds for Moderate evidence towards pathogenicity (LR >4.3 & <=18.7) (PP4_Moderate met; PMID: 31131967, 31853058). In summary, this variant meets the criteria to be classified as a Likely pathogenic variant for BRCA2-related cancer predisposition based on the ACMG/AMP criteria applied as specified by the ENIGMA BRCA1/2 VCEP (PVS1_Moderate (RNA), PM3, PP4_Moderate). -

Familial cancer of breast Pathogenic:1

Oct 10, 2022

Baylor Genetics

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

not specified Uncertain:1

Feb 28, 2017

Quest Diagnostics Nichols Institute San Juan Capistrano

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.46
CADD	Uncertain	23
DANN	Benign	0.63

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.97
SpliceAI score (max)		0.95		Details are displayed if max score is > 0.2
DS_AG_spliceai		0.95		Position offset: 1
DS_AL_spliceai		0.77		Position offset: 3

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

LitVar

Other links and lift over

dbSNP: rs568027879; hg19: chr13-32903577;