chr13-32341112-CTT-C

Position:

• chr13-32341112-CTT-C

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.6761_6762del​(p.Phe2254TyrfsTer6) variant causes a frameshift change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Pathogenic (★★★). Variant results in nonsense mediated mRNA decay.

• Frequency: Genomes: not found (cov: 32)
• Consequence: BRCA2 NM_000059.4 frameshift
• Clinical Significance: Pathogenic reviewed by expert panel P:15
• Conservation: PhyloP100: -0.0380

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 13-32341112-CTT-C is Pathogenic according to our data. Variant chr13-32341112-CTT-C is described in ClinVar as [Pathogenic]. Clinvar id is 52178.Status of the report is reviewed_by_expert_panel, 3 stars. Variant chr13-32341112-CTT-C is described in Lovd as [Pathogenic]. Variant chr13-32341112-CTT-C is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
BRCA2	NM_000059.4	c.6761_6762del	p.Phe2254TyrfsTer6	frameshift_variant	11/27	ENST00000380152.8	NP_000050.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
BRCA2	ENST00000380152.8	c.6761_6762del	p.Phe2254TyrfsTer6	frameshift_variant	11/27	5	NM_000059.4	ENSP00000369497	A2

Frequencies

GnomAD3 genomes Cov.: 32

We have no GnomAD4 exomes data on this position. Probably position not covered by the project.

GnomAD4 genome Cov.: 32

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:15

Revision: reviewed by expert panel

Submissions by phenotype

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

Pathogenic, no assertion criteria provided	clinical testing	Breast Cancer Information Core (BIC) (BRCA2)	Jun 12, 2000	- -
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	BRCAlab, Lund University	Mar 02, 2020	- -
Pathogenic, criteria provided, single submitter	clinical testing	Consortium of Investigators of Modifiers of BRCA1/2 (CIMBA), c/o University of Cambridge	Oct 02, 2015	- -

not provided Pathogenic:3

Pathogenic, criteria provided, single submitter	clinical testing	Quest Diagnostics Nichols Institute San Juan Capistrano	Feb 27, 2018	- -
Pathogenic, criteria provided, single submitter	clinical testing	Institute of Medical Genetics and Applied Genomics, University Hospital Tübingen	Oct 23, 2020	- -
Pathogenic, criteria provided, single submitter	clinical testing	GeneDx	Jun 12, 2024	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; Truncating variants in this gene are considered pathogenic by a well-established clinical consortium and/or database; Not observed at significant frequency in large population cohorts (gnomAD); Also known as 6758_6759del, 6989delTT; This variant is associated with the following publications: (PMID: 26915939, 28814288, 31447099, 31948886, 30787465, 28831036, 29446198, 28525389, 29922827, 32438681) -

Hereditary cancer-predisposing syndrome Pathogenic:3

Pathogenic, criteria provided, single submitter	clinical testing	Color Diagnostics, LLC DBA Color Health	Mar 22, 2021	This variant deletes 2 nucleotides in exon 11 of the BRCA2 gene, creating a frameshift and premature translation stop signal. This variant is expected to result in an absent or non-functional protein product. To our knowledge, this variant has been reported in an individual with suspected hereditary breast/ovarian cancer (PMID: 26915939). 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 24, 2021	The c.6761_6762delTT pathogenic mutation, located in coding exon 10 of the BRCA2 gene, results from a deletion of two nucleotides at nucleotide positions 6761 to 6762, causing a translational frameshift with a predicted alternate stop codon (p.F2254Yfs*6). This variant has been reported in several individuals and/or families with Hereditary Breast and Ovarian Cancer syndrome (Seymour HJ et al. S Afr Med J, 2016 Feb;106:264-7; Elimam AA et al. BMC Med. Genet., 2017 08;18:85; Rebbeck TR et al. Hum Mutat, 2018 05;39:593-620; Santonocito C et al. Cancers (Basel), 2020 May;12:). This variant is considered to be rare based on population cohorts in the Genome Aggregation Database (gnomAD). 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. -
Pathogenic, criteria provided, single submitter	curation	Sema4, Sema4	Dec 14, 2020	- -

Hereditary breast ovarian cancer syndrome Pathogenic:3

Pathogenic, criteria provided, single submitter	clinical testing	Women's Health and Genetics/Laboratory Corporation of America, LabCorp	Apr 06, 2022	Variant summary: BRCA2 c.6761_6762delTT (p.Phe2254TyrfsX6) 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 251352 control chromosomes (gnomAD). Multiple publications, c.6761_6762delTT, have cited the variant in affected individuals (example, Dougherty_2017, Maxwell_2017, Seymour_2016). Multiple clinical diagnostic laboratories, an expert panel (ENIGMA) and a consortium (CIMBA) have submitted clinical-significance assessments for this variant to ClinVar after 2014 and classified the variant as pathogenic. Based on the evidence outlined above, the variant was classified as pathogenic. -
Pathogenic, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Dec 12, 2023	This sequence change creates a premature translational stop signal (p.Phe2254Tyrfs*6) 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: 28814288). ClinVar contains an entry for this variant (Variation ID: 52178). For these reasons, this variant has been classified as Pathogenic. -
Pathogenic, criteria provided, single submitter	clinical testing	National Health Laboratory Service, Universitas Academic Hospital and University of the Free State	Apr 19, 2022	- -

BRCA2-related disorder Pathogenic:1

Pathogenic, no assertion criteria provided

clinical testing

PreventionGenetics, part of Exact Sciences

Jul 16, 2024

The BRCA2 c.6761_6762delTT variant is predicted to result in a frameshift and premature protein termination (p.Phe2254Tyrfs*6). This variant has been reported in multiple individuals with breast or ovarian cancer (see for example, Seymour et al. 2016. PubMed ID: 26915939; Elimam et al. 2017. PubMed ID: 28814288; Table S1, Rebbeck et al. 2018. PubMed ID: 29446198). This variant has not been reported in a large population database, indicating it is rare. This variant has been classified as pathogenic by other institutions in ClinVar (https://www.ncbi.nlm.nih.gov/clinvar/variation/52178/). Frameshift variants in BRCA2 are expected to be pathogenic. This variant is interpreted as pathogenic. -

Familial cancer of breast Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Baylor Genetics

Dec 08, 2023

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Computational scores

Source: dbNSFP v4.3

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: rs80359624; hg19: chr13-32915249;