13-32362595-G-A

Position:

• chr13-32362595-G-A

Variant summary

Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PVS1 PM2 PP5_Very_Strong

The NM_000059.4(BRCA2):​c.7878G>A​(p.Trp2626Ter) variant causes a stop gained change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000657 in 152,164 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 Pathogenic (★★★). Variant results in nonsense mediated mRNA decay.

• Frequency: Genomes: 𝑓 0.0000066 (0 hom., cov: 32)
• Consequence: BRCA2 NM_000059.4 stop_gained
• Clinical Significance: Pathogenic reviewed by expert panel P:14 U:1
• Conservation: PhyloP100: 9.89

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 Pathogenic. Variant got 18 ACMG points.

• PVS1: Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 13-32362595-G-A is Pathogenic according to our data. Variant chr13-32362595-G-A is described in ClinVar as [Pathogenic]. Clinvar id is 38124.Status of the report is reviewed_by_expert_panel, 3 stars. Variant chr13-32362595-G-A is described in Lovd as [Pathogenic]. Variant chr13-32362595-G-A is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
BRCA2	NM_000059.4	c.7878G>A	p.Trp2626Ter	stop_gained	17/27	ENST00000380152.8	NP_000050.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
BRCA2	ENST00000380152.8	c.7878G>A	p.Trp2626Ter	stop_gained	17/27	5	NM_000059.4	ENSP00000369497	A2

Frequencies

GnomAD3 genomes AF: 0.00000657 AC: 1 AN: 152164 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.000192

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

GnomAD4 exome Cov.: 33

GnomAD4 genome AF: 0.00000657 AC: 1 AN: 152164 Hom.: 0 Cov.: 32 AF XY: 0.0000135 AC XY: 1 AN XY: 74334

Gnomad4 AFR AF: 0.00

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.000192

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: Pathogenic

Submissions summary: Pathogenic:14 Uncertain:1

Revision: reviewed by expert panel

Submissions by phenotype

Breast-ovarian cancer, familial, susceptibility to, 2 Pathogenic:4 Uncertain:1

Pathogenic, no assertion criteria provided	clinical testing	Sharing Clinical Reports Project (SCRP)	Mar 12, 2013	- -
Uncertain significance, no assertion criteria provided	clinical testing	Breast Cancer Information Core (BIC) (BRCA2)	Feb 20, 2013	- -
Pathogenic, criteria provided, single submitter	clinical testing	Consortium of Investigators of Modifiers of BRCA1/2 (CIMBA), c/o University of Cambridge	Oct 02, 2015	- -
Pathogenic, reviewed by expert panel	curation	Evidence-based Network for the Interpretation of Germline Mutant Alleles (ENIGMA)	Sep 08, 2016	Variant allele predicted to encode a truncated non-functional protein. -
Pathogenic, criteria provided, single submitter	clinical testing	Counsyl	Sep 07, 2016	- -

Hereditary breast ovarian cancer syndrome Pathogenic:3

Pathogenic, criteria provided, single submitter	clinical testing	Women's Health and Genetics/Laboratory Corporation of America, LabCorp	Aug 07, 2023	Variant summary: BRCA2 c.7878G>A (p.Trp2626X) results in a premature termination codon, predicted to cause a truncation of the encoded protein or absence of the protein due to nonsense mediated decay, which are commonly known mechanisms for disease. Variants downstream of this position have been classified as pathogenic by our laboratory. The variant was absent in 251276 control chromosomes. c.7878G>A has been reported in the literature in individuals affected with Hereditary Breast And Ovarian Cancer Syndrome (Carney_2010, Kwong_2012, Couch_2015, Hondow_2011). These data indicate that the variant is likely to be associated with disease. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. The following publications have been ascertained in the context of this evaluation (PMID: 21702907, 21218378, 22970155, 25452441). Eight submitters have cited clinical-significance assessments for this variant to ClinVar after 2014. All submitters classified the variant as pathogenic/likely pathogenic. Based on the evidence outlined above, the variant was classified as pathogenic. -
Pathogenic, no assertion criteria provided	research	Research Molecular Genetics Laboratory, Women's College Hospital, University of Toronto	Jan 31, 2014	- -
Pathogenic, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Dec 29, 2023	This sequence change creates a premature translational stop signal (p.Trp2626*) in the BRCA2 gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in BRCA2 are known to be pathogenic (PMID: 20104584). This variant is not present in population databases (gnomAD no frequency). This premature translational stop signal has been observed in individual(s) with hereditary breast and ovarian cancer (PMID: 21218378, 22970155, 25452441, 26187060). This variant is also known as 8106G>A. ClinVar contains an entry for this variant (Variation ID: 38124). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. For these reasons, this variant has been classified as Pathogenic. -

not provided Pathogenic:2

Pathogenic, criteria provided, single submitter	clinical testing	Revvity Omics, Revvity	Nov 15, 2019	- -
Pathogenic, criteria provided, single submitter	clinical testing	GeneDx	Jan 24, 2023	Nonsense variant predicted to result in protein truncation or nonsense mediated decay in a gene for which loss-of-function is a known mechanism of disease; Reported in individuals with personal or family history of breast and/or ovarian cancer (Carney et al., 2010; Kwong et al., 2012; Couch et al., 2015; Ow et al., 2019); Not observed at significant frequency in large population cohorts (gnomAD); Truncating variants in this gene are considered pathogenic by a well-established clinical consortium and/or database; This variant is associated with the following publications: (PMID: 30093976, 29487695, 29937436, 28888541, 21702907, 21218378, 26187060, 27157322, 22970155, 25452441, 32467295, 30702160, 29446198, 30787465, 33858678, 34022715, 25085752, 32091409, Huang_2021_Case Report, 30875412, 31825140) -

Hereditary cancer-predisposing syndrome Pathogenic:2

Pathogenic, criteria provided, single submitter	clinical testing	Color Diagnostics, LLC DBA Color Health	Aug 22, 2022	This variant changes 1 nucleotide in exon 17 of the BRCA2 gene, creating a premature translation stop signal. This variant is expected to result in an absent or non-functional protein product. This variant has been detected in at least 10 individuals affected with breast cancer (PMID: 21218378, 25452441, 26187060, 33471991; Color internal data; Leiden Open Variation Database DB-ID BRCA2_005264) and one proband who also had cancer of the brain (PMID: 21218378). 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. -
Pathogenic, criteria provided, single submitter	clinical testing	Ambry Genetics	Nov 17, 2022	The p.W2626* pathogenic mutation (also known as c.7878G>A) located in coding exon 16 of the BRCA2 gene, results from a G to A substitution at nucleotide position 7878. This changes the amino acid from a tryptophan to a stop codon within coding exon 16. This alteration has been reported in multiple high-risk breast and/or ovarian cancer patients in the literature (Carney ME et al. Hawaii Med J. 2010 Nov;69:268-71; Couch FJ et al. J. Clin. Oncol. 2015 Feb;33:304-11; Kwong A et al. PLoS ONE. 2012 Sep;7:e43994; Kwong A et al. J. Med. Genet. 2016 Jan;53:15-23; Rebbeck TR et al. Hum Mutat. 2018 May;39(5):593-620). In addition to the clinical data presented in the literature, this alteration is expected to result in loss of function by premature protein truncation or nonsense-mediated mRNA decay. As such, this alteration is interpreted as a disease-causing mutation. -

BRCA2-related disorder Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

PreventionGenetics, part of Exact Sciences

Aug 14, 2023

The BRCA2 c.7878G>A variant is predicted to result in premature protein termination (p.Trp2626*). This variant has been reported in several individuals with a personal and/or family history of breast and/or ovarian cancer (see for example, Lilyquist J et al 2017. PubMed ID: 28888541; Kwong A et al 2015. PubMed ID: 26187060; Couch FJ et al 2014. PubMed ID: 25452441; Carney ME et al 2010. PubMed ID: 21218378; Kwong A et al 2012. PubMed ID: 22970155). This variant has not been reported in a large population database (http://gnomad.broadinstitute.org), indicating it is rare in the general population. Nonsense variants in BRCA2 are expected to be pathogenic. This variant is classified as pathogenic by several submitters in ClinVar, including by an expert panel (https://www.ncbi.nlm.nih.gov/clinvar/variation/38124/). This variant is interpreted as pathogenic. -

Malignant tumor of breast Pathogenic:1

Pathogenic, no assertion criteria provided

clinical testing

Department of Pathology and Laboratory Medicine, Sinai Health System

-

The BRCA2 p.Trp2626X variant was identified in 6 of 1438 proband chromosomes (frequency: 0.004) from multiethnic Asian individuals or families with high risk breast cancer; the variant being frequent in the Hong Kong population (Kwong 2012, Kwong 2015). The variant was also identified in dbSNP (ID: rs80359013) “With Pathogenic” allele, ClinVar (classified as pathogenic, reviewed by expert panel; submitters: ENIGMA, Counsyl, Invitae, Ambry Genetics, GeneDx, SCRP and CIMBA), Clinvitae (4x), BIC Database (1x, with unknown clinical importance, class 3-uncertain significance), and ARUP Laboratories (5-definitely pathogenic). The variant was not identified in GeneInsight-COGR, Cosmic, MutDB, LOVD 3.0, UMD-LSDB, Zhejiang Colon Cancer Database, the 1000 Genomes Project, the NHLBI GO Exome Sequencing Project or the Exome Aggregation Consortium (August 8th 2016) control databases. The variant was also identified by our laboratory in 3 individuals at risk of familial breast cancer. The p.Trp2626X variant leads to a premature stop codon at position 2626, which is predicted to lead to a truncated or absent protein and loss of function. Loss of function variants of the BRCA2 gene are an established mechanism of disease in hereditary breast and ovarian cancer and is the type of variant expected to cause the disorder. In summary, based on the above information this variant meets our laboratory’s criteria to be classified as pathogenic. -

Familial cancer of breast Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Baylor Genetics

Mar 15, 2024

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.58	D
BayesDel_noAF	Pathogenic	0.60
CADD	Pathogenic	46
DANN	Uncertain	1.0
Eigen	Pathogenic	1.1
Eigen_PC	Pathogenic	0.96
FATHMM_MKL	Pathogenic	0.97	D
MutationTaster	Benign	1.0	A;A
Vest4		0.87
GERP RS		5.7

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.0		Details are displayed if max score is > 0.2

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

Publications

LitVar

Other links and lift over

dbSNP: rs80359013; hg19: chr13-32936732;