rs80359016

chr13-32362625-T-Achr13-32362625-T-G

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.7908T>A(p.Cys2636Ter) variant causes a stop gained change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Pathogenic (★★★). Synonymous variant affecting the same amino acid position (i.e. C2636C) has been classified as Likely benign. Variant results in nonsense mediated mRNA decay.

• Frequency: Genomes: not found (cov: 32)
• Consequence: BRCA2 NM_000059.4 stop_gained
• Clinical Significance: Pathogenic reviewed by expert panel P:6
• Conservation: PhyloP100: 0.234

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 13-32362625-T-A is Pathogenic according to our data. Variant chr13-32362625-T-A is described in ClinVar as [Pathogenic]. Clinvar id is 52433.Status of the report is reviewed_by_expert_panel, 3 stars. Variant chr13-32362625-T-A is described in Lovd as [Pathogenic]. Variant chr13-32362625-T-A is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
BRCA2	NM_000059.4	c.7908T>A	p.Cys2636Ter	stop_gained	17/27	ENST00000380152.8

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
BRCA2	ENST00000380152.8	c.7908T>A	p.Cys2636Ter	stop_gained	17/27	5	NM_000059.4	A2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 33

GnomAD4 genome Cov.: 32

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:6

Revision: reviewed by expert panel

Submissions by phenotype

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

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, no assertion criteria provided	clinical testing	Breast Cancer Information Core (BIC) (BRCA2)	-	- -
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, no assertion criteria provided	clinical testing	Department of Pathology and Laboratory Medicine, Sinai Health System	-	The p.Cys2636X variant has been previously reported in 1 of 880 proband chromosomes in an individual with breast and/or ovarian cancer; population controls were not included in this study (Lubinski 2004). It is listed in the dbSNP database as coming from a "clinical source" (ID#: rs80359016) with no frequency information provided, so the population frequency is not known. The p.Cys2636X variant leads to a premature stop codon at position 2636, which is predicted to cause a truncated or absent protein product and loss of function. Loss of function of the BRCA2 gene is an established disease mechanism in hereditary breast and ovarian cancer patients. In summary, based on the above information, this variant is classified as pathogenic. -

Hereditary breast ovarian cancer syndrome Pathogenic:2

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	Invitae	Oct 17, 2022	For these reasons, this variant has been classified as Pathogenic. ClinVar contains an entry for this variant (Variation ID: 52433). This variant is also known as 8136T>A. This premature translational stop signal has been observed in individual(s) with a personal and/or family history of BRCA2-related cancers (PMID: 15131399, 29446198). This variant is not present in population databases (gnomAD no frequency). This sequence change creates a premature translational stop signal (p.Cys2636*) 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). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.49	D
BayesDel_noAF	Pathogenic	0.47
Cadd	Pathogenic	37
Dann	Uncertain	0.99
Eigen	Pathogenic	0.76
Eigen_PC	Uncertain	0.60
FATHMM_MKL	Benign	0.67	D
MutationTaster	Benign	1.0	A;A
Vest4		0.89
GERP RS		4.5

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: rs80359016; hg19: chr13-32936762;