13-32332681-AG-A

Position:

• chr13-32332681-AG-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.1205del​(p.Gly402ValfsTer2) variant causes a frameshift change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000657 in 152,230 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Pathogenic (★★★). Variant results in nonsense mediated mRNA decay.

• Frequency: Genomes: 𝑓 0.0000066 (0 hom., cov: 32)
• Consequence: BRCA2 NM_000059.4 frameshift
• Clinical Significance: Pathogenic reviewed by expert panel P:13
• Conservation: PhyloP100: 0.594

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 13-32332681-AG-A is Pathogenic according to our data. Variant chr13-32332681-AG-A is described in ClinVar as [Pathogenic]. Clinvar id is 37730.Status of the report is reviewed_by_expert_panel, 3 stars. Variant chr13-32332681-AG-A is described in Lovd as [Pathogenic]. Variant chr13-32332681-AG-A is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
BRCA2	NM_000059.4	c.1205del	p.Gly402ValfsTer2	frameshift_variant	10/27	ENST00000380152.8	NP_000050.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
BRCA2	ENST00000380152.8	c.1205del	p.Gly402ValfsTer2	frameshift_variant	10/27	5	NM_000059.4	ENSP00000369497	A2

Frequencies

GnomAD3 genomes AF: 0.00000657 AC: 1 AN: 152230 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.0000241

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: 0.00

Gnomad NFE AF: 0.00

Gnomad OTH AF: 0.00

GnomAD4 exome Cov.: 35

GnomAD4 genome AF: 0.00000657 AC: 1 AN: 152230 Hom.: 0 Cov.: 32 AF XY: 0.0000134 AC XY: 1 AN XY: 74372

Gnomad4 AFR AF: 0.0000241

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:13

Revision: reviewed by expert panel

Submissions by phenotype

Breast-ovarian cancer, familial, susceptibility to, 2 Pathogenic:4

Pathogenic, no assertion criteria provided	clinical testing	Sharing Clinical Reports Project (SCRP)	Mar 11, 2008	- -
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, criteria provided, single submitter	clinical testing	Human Genome Sequencing Center Clinical Lab, Baylor College of Medicine	Oct 08, 2018	The c.1205delG (p.Gly402Valfs*2) variant in the BRCA2 gene is predicted to introduce a premature translation termination codon. This variant has been reported in one patient with triple-negative breast cancer (PMID 25428789), one patient with high likelihood of being a mutation carrier predicted by BRCAPRO statistical modeling (PMID 16234499), and multiple individuals who were referred for clinical testing in other clinical labs. This variant is not observed in gnomAD. Therefore, the c.1205delG (p.Gly402Valfs*2) variant in the BRCA2 gene is classified as pathogenic. -
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. -

Hereditary breast ovarian cancer syndrome Pathogenic:4

Pathogenic, criteria provided, single submitter	clinical testing	Women's Health and Genetics/Laboratory Corporation of America, LabCorp	Jan 19, 2017	Variant summary: The BRCA2 c.1205delG (p.Gly402Valfs) variant results in a premature termination codon, predicted to cause a truncated or absent BRCA2 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 (e.g c.1257delT, p.Cys419fs). One in silico tool predicts a damaging outcome for this variant. This variant is absent in 120776 control chromosomes. In addition, multiple clinical diagnostic laboratories/reputable databases classified this variant as pathogenic. Taken together, this variant is classified as pathogenic. -
Pathogenic, no assertion criteria provided	research	Research Molecular Genetics Laboratory, Women's College Hospital, University of Toronto	Jan 31, 2014	- -
Pathogenic, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Sep 23, 2023	This premature translational stop signal has been observed in individual(s) with breast and/or ovarian cancer (PMID: 16234499, 25428789, 26250392). This variant is also known as 1433delG. ClinVar contains an entry for this variant (Variation ID: 37730). For these reasons, this variant has been classified as Pathogenic. This variant is present in population databases (rs397507265, gnomAD 0.01%). This sequence change creates a premature translational stop signal (p.Gly402Valfs*2) 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). -
Pathogenic, criteria provided, single submitter	clinical testing	Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine	Jul 13, 2018	The p.Gly402ValfsX2 variant in BRCA2 has been reported in at least 3 African Ame rican individuals with a personal or family history of breast and/or ovarian can cer (Nanda 2005, Lynce 2015, Churpek 2015). This variant has been identified in 1/8734 African chromosomes by the Genome Aggregation Database (gnomAD, http://gn omad.broadinstitute.org). This variant is predicted to cause a frameshift, which alters the protein?s amino acid sequence beginning at position 402 and leads to a premature termination codon 2 amino acids downstream. This alteration is then predicted to lead to a truncated or absent protein. Heterozygous loss of functi on of the BRCA2 gene is an established disease mechanism in hereditary breast an d ovarian cancer (HBOC). In addition, this variant was classified as Pathogenic on Sept 8, 2016 by the ClinGen-approved ENIGMA expert panel (ClinVar SCV00030040 6.2). In summary, this variant meets criteria to be classified as pathogenic for HBOC in an autosomal dominant manner based upon the presence in probands and th e predicted impact on the protein. ACMG/AMP Criteria applied: PVS1, PM2, PS4_Sup porting. -

not provided Pathogenic:2

Pathogenic, criteria provided, single submitter	clinical testing	Quest Diagnostics Nichols Institute San Juan Capistrano	Dec 31, 2019	The variant results in a shift of the reading frame, and is therefore predicted to result in the loss of a functional protein. Found in at least one patient with expected phenotype for this gene, and found in general population data at a frequency that is consistent with pathogenicity. -
Pathogenic, criteria provided, single submitter	clinical testing	GeneDx	Mar 28, 2024	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; Truncating variants in this gene are considered pathogenic by a well-established clinical consortium and/or database; Observed in individuals with personal and/or family history consistent with pathogenic variants in this gene (PMID: 16234499, 25428789, 26250392, 32832836); Not observed at significant frequency in large population cohorts (gnomAD); Also known as 1433delG; This variant is associated with the following publications: (PMID: 25428789, 26250392, 16234499, 26295337, 26681312, 30720243, 31447099, 32832836) -

BRCA2-related disorder Pathogenic:1

Pathogenic, no assertion criteria provided

clinical testing

PreventionGenetics, part of Exact Sciences

May 23, 2024

The BRCA2 c.1205delG variant is predicted to result in a frameshift and premature protein termination (p.Gly402Valfs*2). This variant (also known as c.1433delG) has been reported in individuals with a personal or family history of breast and/or ovarian cancer (see for example, Nanda et al. 2005. PubMed ID: 16234499; Lynce et al. 2015. PubMed ID: 26250392; Churpek et al. 2015. PubMed ID: 25428789; eMERGE Consortium. 2019. PubMed ID: 31447099. Table S10). This variant was also identified in 1/10030 patients referred for cancer panel testing (Susswein et al. PubMed ID: 26681312. Table S1). This variant is reported in 0.011% of alleles in individuals of African descent in gnomAD and is interpreted as pathogenic by the vast majority of submitters in ClinVar (https://www.ncbi.nlm.nih.gov/clinvar/variation/37730/). Frameshift variants in BRCA2 are expected to be pathogenic. This variant is interpreted as pathogenic. -

Hereditary cancer-predisposing syndrome Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Ambry Genetics

Dec 23, 2022

The c.1205delG pathogenic mutation, located in coding exon 9 of the BRCA2 gene, results from a deletion of one nucleotide at nucleotide position 1205, causing a translational frameshift with a predicted alternate stop codon (p.G402Vfs*2). This mutation has been reported in high-risk African-American breast cancer patients (Nanda R et al. JAMA. 2005; 294:1925-33; Churpek JE et al. Breast Cancer Res Treat. 2015 Jan;149(1):31-9). This alteration was identified in 1/10030 consecutive patients referred for evaluation by an NGS hereditary cancer panel (Susswein LR et al. Genet. Med., 2016 08;18:823-32). Of note, this mutation is also designated as 1433delG 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. -

Familial cancer of breast Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Baylor Genetics

Mar 15, 2022

- -

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: rs397507265; hg19: chr13-32906818;