chr13-32339176-TGA-C

Position:

• chr13-32339176-TGA-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.4821_4823delinsC​(p.Glu1608AspfsTer6) 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 (★★★). Synonymous variant affecting the same amino acid position (i.e. IE1607I?) has been classified as Pathogenic. Variant results in nonsense mediated mRNA decay.

• Frequency: Genomes: not found (cov: 33)
• Consequence: BRCA2 NM_000059.4 frameshift
• Clinical Significance: Pathogenic reviewed by expert panel P:12
• Conservation: PhyloP100: 2.68

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 13-32339176-TGA-C is Pathogenic according to our data. Variant chr13-32339176-TGA-C is described in ClinVar as [Pathogenic]. Clinvar id is 142963.Status of the report is reviewed_by_expert_panel, 3 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
BRCA2	NM_000059.4	c.4821_4823delinsC	p.Glu1608AspfsTer6	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.4821_4823delinsC	p.Glu1608AspfsTer6	frameshift_variant	11/27	5	NM_000059.4	ENSP00000369497	A2

Frequencies

GnomAD3 genomes Cov.: 33

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

GnomAD4 genome Cov.: 33

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:12

Revision: reviewed by expert panel

Submissions by phenotype

Breast-ovarian cancer, familial, susceptibility to, 2 Pathogenic:3

Pathogenic, criteria provided, single submitter	clinical testing	Department of Medical Genetics, Oslo University Hospital	Jul 08, 2015	- -
Pathogenic, criteria provided, single submitter	clinical testing	All of Us Research Program, National Institutes of Health	Aug 28, 2023	This variant deletes 3 nucleotides and inserts 1 nucleotide 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. This variant has been reported in an individual affected with ovarian cancer (PMID: 28888541), 2 individuals affected with breast cancer (Color internal data), and in 25 families eligible for BRCA1/2 testing (PMID: 29339979). 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, 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. -

not provided Pathogenic:3

Pathogenic, criteria provided, single submitter	clinical testing	GeneDx	Nov 06, 2019	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; Not observed in large population cohorts (Lek 2016); Truncating variants in this gene are considered pathogenic by a well-established clinical consortium and/or database; Also known as 5049_5051delTGAinsC; This variant is associated with the following publications: (PMID: 28152038, 29339979, 28888541) -
Pathogenic, criteria provided, single submitter	clinical testing	Quest Diagnostics Nichols Institute San Juan Capistrano	Oct 18, 2019	The variant results in a shift of the reading frame, and is therefore predicted to result in the loss of a functional protein. Found in at least one patient with expected phenotype for this gene, and found in general population data at a frequency that is consistent with pathogenicity. -
Pathogenic, criteria provided, single submitter	clinical testing	Revvity Omics, Revvity	Aug 23, 2023	- -

Hereditary breast ovarian cancer syndrome Pathogenic:3

Pathogenic, criteria provided, single submitter	clinical testing	Women's Health and Genetics/Laboratory Corporation of America, LabCorp	Dec 09, 2022	Variant summary: BRCA2 c.4821_4823delinsC (p.Glu1608AspfsX6) 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 250076 control chromosomes. c.4821_4823delinsC has been reported in the literature in numerous individuals affected with Hereditary Breast And Ovarian Cancer Syndrome (examples: Heramb_2018, Lilyquist_2017). To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. Seven clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014 without evidence for independent evaluation. All laboratories 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	- -
Pathogenic, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Dec 15, 2023	This sequence change creates a premature translational stop signal (p.Glu1608Aspfs*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). Information on the frequency of this variant in the gnomAD database is not available, as this variant may be reported differently in the database. This premature translational stop signal has been observed in individual(s) with hereditary breast and ovarian cancer (PMID: 29339979). ClinVar contains an entry for this variant (Variation ID: 142963). For these reasons, this variant has been classified as Pathogenic. -

Hereditary cancer-predisposing syndrome Pathogenic:2

Pathogenic, criteria provided, single submitter	clinical testing	Ambry Genetics	Oct 07, 2022	The c.4821_4823delTGAinsC pathogenic mutation, located in coding exon 10 of the BRCA2 gene, results from the deletion of 3 nucleotides and insertion of one nucleotide causing a translational frameshift with a predicted alternate stop codon (p.E1608Dfs*6). In a large, clinic-based BRCA1/2 testing cohort in Norway, this alteration was detected in 25 families (Heramb C et al. Hered Cancer Clin Pract, 2018 Jan;16:3). Additionally, this alteration was detected in a patient with ovarian cancer referred for multi-gene panel testing and in a patient who was referred for whole exome sequencing (LaDuca H et al. PLoS ONE, 2017 Feb;12:e0170843; Lilyquist J et al. Gynecol. Oncol., 2017 11;147:375-380). 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	clinical testing	Color Diagnostics, LLC DBA Color Health	Jun 22, 2023	This variant deletes 3 nucleotides and inserts 1 nucleotide 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. This variant has been reported in an individual affected with ovarian cancer (PMID: 28888541), 2 individuals affected with breast cancer (Color internal data), and in 25 families eligible for BRCA1/2 testing (PMID: 29339979). 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. -

Familial cancer of breast Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Baylor Genetics

Apr 28, 2022

- -

Computational scores

Source: dbNSFP v4.3

Splicing

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

Publications

LitVar

Other links and lift over

dbSNP: rs587782854; hg19: chr13-32913313;