rs80359080

Positions:

• chr13-32370433-G-A
• chr13-32370433-G-C
• chr13-32370433-G-T

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.8363G>A​(p.Trp2788Ter) variant causes a stop gained change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,694 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: not found (cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: BRCA2 NM_000059.4 stop_gained
• Clinical Significance: Pathogenic reviewed by expert panel P:9
• Conservation: PhyloP100: 9.94

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 13-32370433-G-A is Pathogenic according to our data. Variant chr13-32370433-G-A is described in ClinVar as [Pathogenic]. Clinvar id is 52564.Status of the report is reviewed_by_expert_panel, 3 stars. Variant chr13-32370433-G-A is described in Lovd as [Pathogenic]. Variant chr13-32370433-G-A is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
BRCA2	NM_000059.4	c.8363G>A	p.Trp2788Ter	stop_gained	19/27	ENST00000380152.8

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
BRCA2	ENST00000380152.8	c.8363G>A	p.Trp2788Ter	stop_gained	19/27	5	NM_000059.4	A2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461694 Hom.: 0 Cov.: 31 AF XY: 0.00000138 AC XY: 1 AN XY: 727170

Gnomad4 AFR exome AF: 0.00

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: 8.99e-7

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:9

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, criteria provided, single submitter	clinical testing	Consortium of Investigators of Modifiers of BRCA1/2 (CIMBA), c/o University of Cambridge	Oct 02, 2015	- -
Pathogenic, criteria provided, single submitter	clinical testing	Quest Diagnostics Nichols Institute San Juan Capistrano	Nov 19, 2015	- -
Pathogenic, no assertion criteria provided	clinical testing	Institute of Human Genetics, Medical University Innsbruck	Feb 11, 2015	- -

Hereditary cancer-predisposing syndrome Pathogenic:2

Pathogenic, criteria provided, single submitter	clinical testing	Color Diagnostics, LLC DBA Color Health	Jan 15, 2020	This variant changes 1 nucleotide in exon 19 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 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	Mar 09, 2022	The p.W2788* pathogenic mutation (also known as c.8363G>A), located in coding exon 18 of the BRCA2 gene, results from a G to A substitution at nucleotide position 8363. This changes the amino acid from a tryptophan to a stop codon within coding exon 18. This alteration has been reported in multiple high-risk breast and/or ovarian cancer families (Machackova E et al. BMC Cancer, 2008 May;8:140; Janaviius R et al. Cancer Genet, 2014 May;207:195-205; Polsler L et al. Eur. J. Hum. Genet. 2016 Feb;24(2):258-62) and has been reported to be a common BRCA2 mutation in Austria (Janaviius R. EPMA J, 2010 Sep;1:397-412). 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. -

Breast and/or ovarian cancer Pathogenic:1

Pathogenic, no assertion criteria provided

clinical testing

CZECANCA consortium

Jun 11, 2019

- -

Malignant tumor of urinary bladder Pathogenic:1

Pathogenic, no assertion criteria provided

research

Laboratory of Urology, Hospital Clinic de Barcelona

-

- -

Hereditary breast ovarian cancer syndrome Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Invitae

Apr 15, 2023

For these reasons, this variant has been classified as Pathogenic. ClinVar contains an entry for this variant (Variation ID: 52564). This premature translational stop signal has been observed in individual(s) with breast and/or ovarian cancer (PMID: 18489799, 25066507). This variant is not present in population databases (gnomAD no frequency). This sequence change creates a premature translational stop signal (p.Trp2788*) 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	0.62	D
BayesDel_noAF	Pathogenic	0.66
CADD	Pathogenic	47
DANN	Uncertain	1.0
Eigen	Pathogenic	0.98
Eigen_PC	Pathogenic	0.86
FATHMM_MKL	Pathogenic	0.99	D
MutationTaster	Benign	1.0	A;A
Vest4		0.88
GERP RS		5.2

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.020		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: rs80359080; hg19: chr13-32944570;