13-32333245-GTTTA-G

Position:

• chr13-32333245-GTTTA-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.1773_1776del​(p.Ile591MetfsTer22) variant causes a frameshift change. The variant allele was found at a frequency of 0.00000137 in 1,459,756 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Pathogenic (★★★). Variant results in nonsense mediated mRNA decay.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: BRCA2 NM_000059.4 frameshift
• Clinical Significance: Pathogenic reviewed by expert panel P:17 U:1
• Conservation: PhyloP100: 4.59

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 13-32333245-GTTTA-G is Pathogenic according to our data. Variant chr13-32333245-GTTTA-G is described in ClinVar as [Pathogenic]. Clinvar id is 51190.Status of the report is reviewed_by_expert_panel, 3 stars. Variant chr13-32333245-GTTTA-G is described in Lovd as [Pathogenic]. Variant chr13-32333245-GTTTA-G is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
BRCA2	NM_000059.4	c.1773_1776del	p.Ile591MetfsTer22	frameshift_variant	10/27	ENST00000380152.8

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
BRCA2	ENST00000380152.8	c.1773_1776del	p.Ile591MetfsTer22	frameshift_variant	10/27	5	NM_000059.4	A2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000137 AC: 2 AN: 1459756 Hom.: 0 AF XY: 0.00000275 AC XY: 2 AN XY: 726206

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: 0.0000233

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:17 Uncertain:1

Revision: reviewed by expert panel

Submissions by phenotype

Breast-ovarian cancer, familial, susceptibility to, 2 Pathogenic:7

Pathogenic, no assertion criteria provided	clinical testing	Breast Cancer Information Core (BIC) (BRCA2)	Sep 18, 2010	- -
Pathogenic, reviewed by expert panel	curation	Evidence-based Network for the Interpretation of Germline Mutant Alleles (ENIGMA)	Apr 22, 2016	Variant allele predicted to encode a truncated non-functional protein. -
Pathogenic, criteria provided, single submitter	clinical testing	Quest Diagnostics Nichols Institute San Juan Capistrano	Feb 25, 2015	- -
Pathogenic, no assertion criteria provided	clinical testing	Breast Cancer Information Core (BIC) (BRCA2)	May 29, 2002	- -
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	Counsyl	Feb 01, 2017	- -
Pathogenic, no assertion criteria provided	clinical testing	BRCAlab, Lund University	Mar 02, 2020	- -

not provided Pathogenic:3 Uncertain:1

Pathogenic, criteria provided, single submitter	clinical testing	Clinical Genetics and Genomics, Karolinska University Hospital	Oct 22, 2018	- -
Uncertain significance, no assertion criteria provided	clinical testing	Department of Pathology and Laboratory Medicine, Sinai Health System	-	- -
Pathogenic, criteria provided, single submitter	clinical testing	GeneDx	Sep 15, 2022	Frameshift 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; Observed in individuals with a personal or family history consistent with pathogenic variants in this gene (Kanaan et al., 2003; Thirthagiri et al., 2008; Novakovic et al., 2012); 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; Also known as 2001_2004del; This variant is associated with the following publications: (PMID: 18393245, 28993434, 32846166, 30787465, 31825140, 32719484, 26295337, 20104584, 12942367, 28439188, 28888541, 29446198, Bahsi2020[case report], 30702160, 24123850, 30875412, 18627636, 22923021) -
Pathogenic, criteria provided, single submitter	clinical testing	Center for Genomic Medicine, Rigshospitalet, Copenhagen University Hospital	Feb 06, 2024	- -

Hereditary breast ovarian cancer syndrome Pathogenic:3

Pathogenic, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Jan 28, 2024	This sequence change creates a premature translational stop signal (p.Ile591Metfs*22) 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 breast cancer (PMID: 12942367, 18393245, 22923021). This variant is also known as 2001delTTAT. ClinVar contains an entry for this variant (Variation ID: 51190). For these reasons, this variant has been classified as Pathogenic. -
Pathogenic, criteria provided, single submitter	clinical testing	Women's Health and Genetics/Laboratory Corporation of America, LabCorp	Apr 18, 2021	Variant summary: BRCA2 c.1773_1776delTTAT (p.Ile591MetfsX22) 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. Truncations downstream of this position have been classified as pathogenic by our laboratory. The variant was absent in 248932 control chromosomes. c.1773_1776delTTAT has been widely reported in the literature in multiple individuals affected with Hereditary Breast And Ovarian Cancer Syndrome (example Rebbeck_2018). These data indicate that the variant is very likely to be associated with disease. Multiple clinical diagnostic laboratories, a consortium (CIMBA) and an expert panel (ENIGMA) have submitted clinical-significance assessments for this variant to ClinVar after 2014 without evidence for independent evaluation. All submitters classified the variant as 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	- -

Hereditary cancer-predisposing syndrome Pathogenic:2

Pathogenic, criteria provided, single submitter	clinical testing	Color Diagnostics, LLC DBA Color Health	Jun 13, 2023	This variant deletes 4 nucleotides in exon 10 of the BRCA2 gene, creating a frameshift and premature translation stop signal. This variant is also known as 2001del4 and 2000del4 in the literature according to the BIC nomenclature. This variant is expected to result in an absent or non-functional protein product. This variant has been reported in at least four individuals affected with breast cancer (PMID: 12942367, 18393245, 18627636, 20174566, 33471991) and in suspected hereditary breast and ovarian cancer families (PMID: 19949876, 21120943, 22923021). 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	May 07, 2024	The c.1773_1776delTTAT pathogenic mutation, located in coding exon 9 of the BRCA2 gene, results from a deletion of 4 nucleotides at nucleotide positions 1773 to 1776, causing a translational frameshift with a predicted alternate stop codon (p.I591Mfs*22). This mutation has been detected in multiple individuals from hereditary breast and/or ovarian cancer cohorts also unselected breast cancer cohorts (Kanaan Y et al. Hum. Genet. 2003 Oct;113:452-60; Thirthagiri E et al. Breast Cancer Res. 2008 Jul;10:R59; Novakovi S et al. Int. J. Oncol. 2012 Nov;41:1619-27; Yildiz T et al. Life Sci 2020 Nov;261:118334; Demir S et al. J BUON;25(3):1337-1347). Of note, this mutation is also designated as 2001del4 in published literature. 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-ovarian cancer, familial, susceptibility to, 1 Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Department of Molecular Diagnostics, Institute of Oncology Ljubljana

Apr 02, 2020

- -

Familial cancer of breast Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Baylor Genetics

Mar 29, 2024

- -

Computational scores

Source: dbNSFP v4.3

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		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: rs80359304; hg19: chr13-32907382;