13-32338860-A-G

Position:

• chr13-32338860-A-G

Variant summary

Our verdict is Likely benign. Variant got -1 ACMG points: 2P and 3B. PM2 BP4_Moderate BP6

The NM_000059.4(BRCA2):​c.4505A>G​(p.Gln1502Arg) 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. 12/19 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. Q1502E) has been classified as Uncertain significance.

• Frequency: Genomes: not found (cov: 33)
• Consequence: BRCA2 NM_000059.4 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:2 B:1
• Conservation: PhyloP100: 1.85

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 Likely_benign. Variant got -1 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.21669546).
• BP6: Variant 13-32338860-A-G is Benign according to our data. Variant chr13-32338860-A-G is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 234199.We mark this variant Likely_benign, oryginal submissions are: {Likely_benign=1, Uncertain_significance=2}.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
BRCA2	NM_000059.4	c.4505A>G	p.Gln1502Arg	missense_variant	11/27	ENST00000380152.8

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
BRCA2	ENST00000380152.8	c.4505A>G	p.Gln1502Arg	missense_variant	11/27	5	NM_000059.4	A2

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 35

GnomAD4 genome Cov.: 33

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:2 Benign:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Hereditary cancer-predisposing syndrome Uncertain:1 Benign:1

Likely benign, criteria provided, single submitter	curation	University of Washington Department of Laboratory Medicine, University of Washington	Mar 23, 2023	Missense variant in a coldspot region where missense variants are very unlikely to be pathogenic (PMID:31911673). -
Uncertain significance, criteria provided, single submitter	clinical testing	Ambry Genetics	Apr 18, 2024	The p.Q1502R variant (also known as c.4505A>G), located in coding exon 10 of the BRCA2 gene, results from an A to G substitution at nucleotide position 4505. The glutamine at codon 1502 is replaced by arginine, an amino acid with highly similar properties. In a population-based study of Chinese women, this variant was detected in 1/645 breast cancer patients but was not seen in 342 women with benign breast disease or 319 healthy controls (Suter NM et al. Cancer Epidemiol Biomarkers Prev. 2004 Feb;13:181-9). This variant was also identified in 1 of 1009 patients amongst a cohort of Chinese patients with a personal history of pancreatic ductal adenocarcinoma (Yin L et al. JAMA Netw Open, 2022 Feb;5:e2148721). This amino acid position is poorly conserved in available vertebrate species. In addition, this alteration is predicted to be tolerated by in silico analysis. Based on the available evidence, the clinical significance of this variant remains unclear. -

not provided Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Quest Diagnostics Nichols Institute San Juan Capistrano

Dec 28, 2022

It has not been reported in large, multi-ethnic general populations (http://gnomad.broadinstitute.org). In the published literature, the variant has been reported in breast cancer association studies (PMIDs: 14973102 (2004) and 31825140 (2019)). Additionally, the variant has been reported both as likely deleterious (PMID: 14973102 (2004)) and as having a decreased association with disease (PMID: 31853058 (2020)). Analysis of this variant using bioinformatics tools for the prediction of the effect of amino acid changes on protein structure and function yielded predictions that this variant is benign. Based on the available information, we are unable to determine the clinical significance of this variant. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.095
BayesDel_addAF	Benign	-0.073	T
BayesDel_noAF	Benign	-0.34
CADD	Benign	15
DANN	Uncertain	0.99
Eigen	Benign	-0.47
Eigen_PC	Benign	-0.43
FATHMM_MKL	Benign	0.57	D
M_CAP	Benign	0.037	D
MetaRNN	Benign	0.22	T;T
MetaSVM	Benign	-0.90	T
MutationTaster	Benign	1.0	N;N
PrimateAI	Benign	0.24	T
PROVEAN	Uncertain	-3.1	D;D
REVEL	Benign	0.17
Sift	Uncertain	0.013	D;D
Sift4G	Uncertain	0.052	T;T
Vest4		0.32
MutPred		0.21		Gain of phosphorylation at T1499 (P = 0.1043);Gain of phosphorylation at T1499 (P = 0.1043);
MVP		0.88
MPC		0.031
ClinPred		0.20	T
GERP RS		3.4
gMVP		0.34

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: rs876660919; hg19: chr13-32912997;