13-32340788-AATAATCAC-A

Position:

• chr13-32340788-AATAATCAC-A

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.6434_6441del​(p.Asn2145IlefsTer3) 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. N2145N) has been classified as Likely benign. 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:7
• Conservation: PhyloP100: 1.60

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 13-32340788-AATAATCAC-A is Pathogenic according to our data. Variant chr13-32340788-AATAATCAC-A is described in ClinVar as [Pathogenic]. Clinvar id is 38044.Status of the report is reviewed_by_expert_panel, 3 stars. Variant chr13-32340788-AATAATCAC-A is described in Lovd as [Pathogenic]. Variant chr13-32340788-AATAATCAC-A is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
BRCA2	NM_000059.4	c.6434_6441del	p.Asn2145IlefsTer3	frameshift_variant	11/27	ENST00000380152.8

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
BRCA2	ENST00000380152.8	c.6434_6441del	p.Asn2145IlefsTer3	frameshift_variant	11/27	5	NM_000059.4	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:7

Revision: reviewed by expert panel

Submissions by phenotype

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

Pathogenic, no assertion criteria provided	clinical testing	Sharing Clinical Reports Project (SCRP)	Feb 16, 2006	- -
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. -
Pathogenic, criteria provided, single submitter	clinical testing	Consortium of Investigators of Modifiers of BRCA1/2 (CIMBA), c/o University of Cambridge	Oct 02, 2015	- -

Hereditary breast ovarian cancer syndrome Pathogenic:2

Pathogenic, criteria provided, single submitter	clinical testing	Women's Health and Genetics/Laboratory Corporation of America, LabCorp	Jun 13, 2021	Variant summary: BRCA2 c.6434_6441delATAATCAC (p.Asn2145IlefsX3) 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 230948 control chromosomes. c.6434_6441delATAATCAC has been reported in the literature in individuals/families affected with Hereditary Breast And Ovarian Cancer Syndrome (example Rebbeck_2018, Litton_2012). To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. Two clinical diagnostic laboratories, an expert panel (ENIGMA) and a consortium (CIMBA) have submitted clinical-significance assessments for this variant to ClinVar after 2014 without evidence for independent evaluation. All submitters classified the variant as pathogenic. Based on the evidence outlined above, the variant was classified as pathogenic. -
Pathogenic, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Jan 19, 2022	This sequence change creates a premature translational stop signal (p.Asn2145Ilefs*3) 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). For these reasons, this variant has been classified as Pathogenic. ClinVar contains an entry for this variant (Variation ID: 38044). This variant is also known as 6662del8. This premature translational stop signal has been observed in individual(s) with breast and/or ovarian cancer (PMID: 21913181). This variant is not present in population databases (gnomAD no frequency). -

not provided Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

GeneDx

Jan 22, 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; Observed in individuals with a personal or family history consistent with pathogenic variants in this gene (Litton 2012); 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 6662_6669delATAATCAC or 6662del8; This variant is associated with the following publications: (PMID: 21913181) -

Hereditary cancer-predisposing syndrome Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Ambry Genetics

Sep 14, 2023

The c.6434_6441delATAATCAC pathogenic mutation, located in coding exon 10 of the BRCA2 gene, results from a deletion of 8 nucleotides at nucleotide positions 6434 to 6441, causing a translational frameshift with a predicted alternate stop codon (p.N2145Ifs*3). This alteration was identified in a hereditary breast and ovarian cancer cohort (Litton JK et al. Cancer 2012 Jan;118(2):321-5). Of note, this alteration is also known as 6662del8 in published literature. 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. -

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: rs397507371; hg19: chr13-32914925;