rs80359355

chr13-32337188-A-ATT

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.2833_2834insTT(p.Lys945IlefsTer16) 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:10
• Conservation: PhyloP100: 2.37

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 13-32337188-A-ATT is Pathogenic according to our data. Variant chr13-32337188-A-ATT is described in ClinVar as [Pathogenic]. Clinvar id is 125995.Status of the report is reviewed_by_expert_panel, 3 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
BRCA2	NM_000059.4	c.2833_2834insTT	p.Lys945IlefsTer16	frameshift_variant	11/27	ENST00000380152.8

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
BRCA2	ENST00000380152.8	c.2833_2834insTT	p.Lys945IlefsTer16	frameshift_variant	11/27	5	NM_000059.4	A2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 33

GnomAD4 genome Cov.: 32

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:10

Revision: reviewed by expert panel

Submissions by phenotype

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

Pathogenic, no assertion criteria provided	clinical testing	Breast Cancer Information Core (BIC) (BRCA2)	Feb 20, 2004	- -
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, 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:2

Pathogenic, criteria provided, single submitter	clinical testing	Quest Diagnostics Nichols Institute San Juan Capistrano	Oct 26, 2020	This frameshift variant causes the premature termination of BRCA2 protein synthesis. To the best of our knowledge, the variant has not been reported in the published literature. This variant has not been reported in large, multi-ethnic general populations. Internal laboratory data indicates that this variant was detected in an individual with a phenotype consistent with disease. Based on the available information, this variant is classified as pathogenic. -
Pathogenic, criteria provided, single submitter	clinical testing	GeneDx	Jun 07, 2021	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 at significant frequency in large population cohorts (Lek et al., 2016); Truncating variants in this gene are considered pathogenic by a well-established clinical consortium and/or database; Has not been previously published as pathogenic or benign to our knowledge; Also known as 3061_3062insTT; This variant is associated with the following publications: (PMID: 10923033, 27535533, 32719484) -

Hereditary cancer-predisposing syndrome Pathogenic:2

Pathogenic, criteria provided, single submitter	clinical testing	Ambry Genetics	Feb 25, 2022	The c.2833_2834insTT pathogenic mutation, located in coding exon 10 of the BRCA2 gene, results from an insertion of two nucleotides at position 2833, causing a translational frameshift with a predicted alternate stop codon (p.K945Ifs*16). 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	Jan 15, 2020	This variant inserts 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. 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. -

Hereditary breast ovarian cancer syndrome Pathogenic:2

Pathogenic, criteria provided, single submitter	clinical testing	Invitae	Jan 06, 2024	This sequence change creates a premature translational stop signal (p.Lys945Ilefs*16) 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 BRCA2-related conditions (PMID: 10923033). ClinVar contains an entry for this variant (Variation ID: 125995). 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	Oct 31, 2022	Variant summary: BRCA2 c.2833_2834insTT (p.Lys945IlefsX16) 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 250652 control chromosomes. c.2833_2834insTT has been reported in the literature in individuals affected with Hereditary Breast And Ovarian Cancer Syndrome (Rebbeck_2018). 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. -

Familial cancer of breast Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Baylor Genetics

Apr 25, 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: rs80359355; hg19: chr13-32911325;