13-32370492-CT-CTT

Variant names:

• chr13-32370492-C-CT
• rs1555287643
• NM_000059.4:c.8426dupT

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.8426dupT​(p.Ser2810GlnfsTer2) 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 (★★★). Synonymous variant affecting the same amino acid position (i.e. F2809F) has been classified as Likely benign. 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:2
• Conservation: PhyloP100: 7.95

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 13-32370492-C-CT is Pathogenic according to our data. Variant chr13-32370492-C-CT is described in ClinVar as [Pathogenic]. Clinvar id is 409460.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.8426dupT	p.Ser2810GlnfsTer2	frameshift_variant	Exon 19 of 27	ENST00000380152.8	NP_000050.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
BRCA2	ENST00000380152.8	c.8426dupT	p.Ser2810GlnfsTer2	frameshift_variant	Exon 19 of 27	5	NM_000059.4	ENSP00000369497.3
BRCA2	ENST00000530893.7	c.8057dupT	p.Ser2687GlnfsTer2	frameshift_variant	Exon 19 of 27	1		ENSP00000499438.2
BRCA2	ENST00000614259.2	n.*484dupT		non_coding_transcript_exon_variant	Exon 18 of 26	2		ENSP00000506251.1
BRCA2	ENST00000614259	n.*484dupT		3_prime_UTR_variant	Exon 18 of 25	2		ENSP00000506251.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 32

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:2

Revision: reviewed by expert panel

Submissions by phenotype

Breast-ovarian cancer, familial, susceptibility to, 2 Pathogenic:1

Dec 15, 2017

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 breast ovarian cancer syndrome Pathogenic:1

Jul 22, 2016

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

For these reasons, this variant has been classified as Pathogenic. While this particular variant has not been reported in the literature, truncating variants in BRCA2 are known to be pathogenic (PMID: 20104584). This sequence change inserts 1 nucleotide in exon 19 of the BRCA2 mRNA (c.8426dupT), causing a frameshift at codon 2810. This creates a premature translational stop signal (p.Ser2810Glnfs*2) and is expected to result in an absent or disrupted protein product. -

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: rs1555287643; hg19: chr13-32944629;