chr13-32398318-A-G

Position:

• chr13-32398318-A-G

Variant summary

Our verdict is Uncertain significance. Variant got 1 ACMG points: 2P and 1B. PM2 BP4

The NM_000059.4(BRCA2):​c.9805A>G​(p.Arg3269Gly) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★).

• Frequency: Genomes: not found (cov: 32)
• Consequence: BRCA2 NM_000059.4 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:5
• Conservation: PhyloP100: 1.67

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 Uncertain_significance. Variant got 1 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.32591096).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
BRCA2	NM_000059.4	c.9805A>G	p.Arg3269Gly	missense_variant	27/27	ENST00000380152.8	NP_000050.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
BRCA2	ENST00000380152.8	c.9805A>G	p.Arg3269Gly	missense_variant	27/27	5	NM_000059.4	ENSP00000369497	A2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:5

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Hereditary cancer-predisposing syndrome Uncertain:2

Uncertain significance, criteria provided, single submitter	clinical testing	Ambry Genetics	Oct 02, 2023	The p.R3269G variant (also known as c.9805A>G), located in coding exon 26 of the BRCA2 gene, results from an A to G substitution at nucleotide position 9805. The arginine at codon 3269 is replaced by glycine, an amino acid with dissimilar properties. This alteration was reported as benign based on sensitivity to PARP inhibitors in a high-throughput in vitro assay performed in a human colorectal adenoma cell line (Ikegami M et al. Nat Commun, 2020 May;11:2573). This amino acid position is well conserved in available vertebrate species. In addition, the in silico prediction for this alteration is inconclusive. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -
Uncertain significance, criteria provided, single submitter	clinical testing	Color Diagnostics, LLC DBA Color Health	Jun 02, 2023	This missense variant replaces arginine with glycine at codon 3269 of the BRCA2 protein. Computational prediction suggests that this variant may not impact protein structure and function (internally defined REVEL score threshold <= 0.5, PMID: 27666373). A functional study has shown that this variant protein does not increase the sensitivity to PARP inhibitors in mammalian cells when compared to the wild-type protein (PMID: 32444794). This variant has not been reported in individuals affected with BRCA2-related disorders in the literature. This variant has not been identified in the general population by the Genome Aggregation Database (gnomAD). The available evidence is insufficient to determine the role of this variant in disease conclusively. Therefore, this variant is classified as a Variant of Uncertain Significance. -

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

Uncertain significance, criteria provided, single submitter

clinical testing

All of Us Research Program, National Institutes of Health

Jun 26, 2023

This missense variant replaces arginine with glycine at codon 3269 of the BRCA2 protein. Computational prediction suggests that this variant may not impact protein structure and function (internally defined REVEL score threshold <= 0.5, PMID: 27666373). A functional study has shown that this variant protein does not increase the sensitivity to PARP inhibitors in mammalian cells when compared to the wild-type protein (PMID: 32444794). This variant has not been reported in individuals affected with BRCA2-related disorders in the literature. This variant has not been identified in the general population by the Genome Aggregation Database (gnomAD). The available evidence is insufficient to determine the role of this variant in disease conclusively. Therefore, this variant is classified as a Variant of Uncertain Significance. -

Familial cancer of breast Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Baylor Genetics

Nov 27, 2023

- -

Hereditary breast ovarian cancer syndrome Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Jan 30, 2024

This sequence change replaces arginine, which is basic and polar, with glycine, which is neutral and non-polar, at codon 3269 of the BRCA2 protein (p.Arg3269Gly). This variant is not present in population databases (gnomAD no frequency). This variant has not been reported in the literature in individuals affected with BRCA2-related conditions. ClinVar contains an entry for this variant (Variation ID: 491393). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is not expected to disrupt BRCA2 protein function with a negative predictive value of 95%. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.17
BayesDel_addAF	Uncertain	0.054	T
BayesDel_noAF	Benign	-0.16
CADD	Benign	21
DANN	Uncertain	1.0
Eigen	Uncertain	0.56
Eigen_PC	Uncertain	0.56
FATHMM_MKL	Uncertain	0.90	D
M_CAP	Uncertain	0.13	D
MetaRNN	Benign	0.33	T;T
MetaSVM	Benign	-1.0	T
MutationTaster	Benign	0.92	D;D
PrimateAI	Benign	0.36	T
PROVEAN	Benign	-2.0	N;N
REVEL	Benign	0.17
Sift	Uncertain	0.0010	D;D
Sift4G	Uncertain	0.0080	D;D
Vest4		0.35
MutPred		0.27		Loss of stability (P = 0.0252);Loss of stability (P = 0.0252);
MVP		0.92
MPC		0.15
ClinPred		0.93	D
GERP RS		5.7
gMVP		0.48

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: rs1555289964; hg19: chr13-32972455;