rs80359704

Variant names:

• chr13-32363453-A-AT
• rs80359704
• NM_000059.4:c.8253dupT

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.8253dupT​(p.Ile2752TyrfsTer12) variant causes a frameshift change involving the alteration of a 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:9
• Conservation: PhyloP100: 7.67

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 13-32363453-A-AT is Pathogenic according to our data. Variant chr13-32363453-A-AT is described in ClinVar as [Pathogenic]. Clinvar id is 38146.Status of the report is reviewed_by_expert_panel, 3 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
BRCA2	NM_000059.4	c.8253dupT	p.Ile2752TyrfsTer12	frameshift_variant	Exon 18 of 27	ENST00000380152.8	NP_000050.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
BRCA2	ENST00000380152.8	c.8253dupT	p.Ile2752TyrfsTer12	frameshift_variant	Exon 18 of 27	5	NM_000059.4	ENSP00000369497.3
BRCA2	ENST00000530893.7	c.7884dupT	p.Ile2629TyrfsTer12	frameshift_variant	Exon 18 of 27	1		ENSP00000499438.2
BRCA2	ENST00000614259.2	n.*311dupT		non_coding_transcript_exon_variant	Exon 17 of 26	2		ENSP00000506251.1
BRCA2	ENST00000614259	n.*311dupT		3_prime_UTR_variant	Exon 17 of 25	2		ENSP00000506251.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 31

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

May 01, 2012

Sharing Clinical Reports Project (SCRP)

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: clinical testing

- -

Oct 02, 2015

Consortium of Investigators of Modifiers of BRCA1/2 (CIMBA), c/o University of Cambridge

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

May 29, 2002

Breast Cancer Information Core (BIC) (BRCA2)

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: clinical testing

- -

Sep 08, 2016

Evidence-based Network for the Interpretation of Germline Mutant Alleles (ENIGMA)

Significance: Pathogenic

Review Status: reviewed by expert panel

Collection Method: curation

Variant allele predicted to encode a truncated non-functional protein. -

Hereditary cancer-predisposing syndrome Pathogenic:2

Sep 07, 2022

Ambry Genetics

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The c.8253dupT pathogenic mutation, located in coding exon 17 of the BRCA2 gene, results from a duplication of T at nucleotide position 8253, causing a translational frameshift with a predicted alternate stop codon (p.I2752Yfs*12). This variant is considered to be rare based on population cohorts in the Genome Aggregation Database (gnomAD). 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. -

May 22, 2020

Color Diagnostics, LLC DBA Color Health

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant inserts 1 nucleotide in exon 18 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 not been reported in individuals affected with hereditary cancer in the literature. 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. -

not provided Pathogenic:1

Mar 15, 2018

GeneDx

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This duplication of one nucleotide in BRCA2 is denoted c.8253dupT at the cDNA level and p.Ile2752TyrfsX12 (I2752YfsX12) at the protein level. Using alternate nomenclature, this variant would be defined as BRCA2 8481insT or 8253_8254insT. The normal sequence, with the base that is duplicated in brackets, is AGAT[dupT]ATTC. The duplication causes a frameshift which changes an Isoleucine to a Tyrosine at codon 2752, and creates a premature stop codon at position 12 of the new reading frame. This variant is predicted to cause loss of normal protein function through either protein truncation or nonsense-mediated mRNA decay. BRCA2 c.8253dupT has been observed as a positive control in a technology validation study, no clinical information was provided (De Leeneer 2015). We consider this variant to be pathogenic. -

Familial cancer of breast Pathogenic:1

Jan 14, 2022

Baylor Genetics

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Hereditary breast ovarian cancer syndrome Pathogenic:1

Apr 21, 2022

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

ClinVar contains an entry for this variant (Variation ID: 38146). For these reasons, this variant has been classified as Pathogenic. This premature translational stop signal has been observed in individual(s) with a personal or family history of breast and/or ovarian cancer (PMID: 29446198). This variant is not present in population databases (gnomAD no frequency). This sequence change creates a premature translational stop signal (p.Ile2752Tyrfs*12) 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

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: rs80359704; hg19: chr13-32937590;