13-32339909-GT-GTT

Position:

• chr13-32339909-GT-GTT

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.5557dupT​(p.Cys1853fs) 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: 𝑓 0.0000066 (0 hom., cov: 33)
  • Failed GnomAD Quality Control
• Consequence: BRCA2 NM_000059.4 frameshift
• Clinical Significance: Pathogenic reviewed by expert panel P:5
• Conservation: PhyloP100: 1.59

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]

BRCA2 (HGNC:):

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 13-32339909-G-GT is Pathogenic according to our data. Variant chr13-32339909-G-GT is described in ClinVar as [Pathogenic]. Clinvar id is 280750.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.5557dupT	p.Cys1853fs	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.5557dupT	p.Cys1853fs	frameshift_variant	11/27	5	NM_000059.4	ENSP00000369497.3
BRCA2	ENST00000530893.7	c.5188dupT	p.Cys1730fs	frameshift_variant	11/27	1		ENSP00000499438.2
BRCA2	ENST00000614259.2	n.5557dupT		non_coding_transcript_exon_variant	10/26	2		ENSP00000506251.1

Frequencies

GnomAD3 genomes AF: 0.00 AC: 1 AN: 152100 Hom.: 0 Cov.: 33 FAILED QC

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00316

Gnomad NFE AF: 0.00

Gnomad OTH AF: 0.00

GnomAD4 exome Cov.: 44

GnomAD4 genome Data not reliable, filtered out with message: AS_VQSR AF: 0.00000657 AC: 1 AN: 152218 Hom.: 0 Cov.: 33 AF XY: 0.0000134 AC XY: 1 AN XY: 74408

Gnomad4 AFR AF: 0.00

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.00

Gnomad4 OTH AF: 0.00

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:5

Revision: reviewed by expert panel

Submissions by phenotype

not provided Pathogenic:2

Pathogenic, criteria provided, single submitter	clinical testing	GeneKor MSA	Jan 09, 2021	This variant is a single base pair insertion in exon 11 of the BRCA2 mRNA, causing a frameshift after codon 1853 and this creates a premature translational stop signal 5 amino acid residues later. This is expected to result in an absent or disrupted protein product. Truncating variants in BRCA2 are known to be pathogenic (PMID: 20104584). This variant has been described in the international literature in individuals undergoing panel testing for hereditary syndrome (PMID: 31159747). The mutation database ClinVar contains entries for this variant (Variation ID: 280750). -
Pathogenic, criteria provided, single submitter	clinical testing	GeneDx	Jul 26, 2016	The c.5557dupT pathogenic variant in the BRCA2 gene has not been reported previously as a pathogenic variant nor as a benign variant, to our knowledge. The c.5557dupT variant causes a frameshift starting with codon Cysteine 1853, changes this amino acid to a Leucine residue, and creates a premature Stop codon at position 5 of the new reading frame, denoted p.Cys1853LeufsX5. This variant is predicted to cause loss of normal protein function either through protein truncation or nonsense-mediated mRNA decay. The c.5557dupT variant was not observed in approximately 6500 individuals of European and African American ancestry in the NHLBI Exome Sequencing Project, indicating it is not a common benign variant in these populations. We interpret c.5557dupT as an expected pathogenic variant. -

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

Pathogenic, reviewed by expert panel

curation

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

Dec 15, 2017

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

Hereditary breast ovarian cancer syndrome Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Aug 24, 2023

ClinVar contains an entry for this variant (Variation ID: 280750). For these reasons, this variant has been classified as Pathogenic. This premature translational stop signal has been observed in individual(s) with breast cancer (PMID: 30720863). This variant is not present in population databases (gnomAD no frequency). This sequence change creates a premature translational stop signal (p.Cys1853Leufs*5) 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). -

Breast carcinoma Pathogenic:1

Pathogenic, no assertion criteria provided

clinical testing

Medical Genetics Laboratory, Umraniye Training and Research Hospital, University of Health Sciences

Sep 12, 2021

- -

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: rs587782011; hg19: chr13-32914046;