rs80359039

chr13-32363234-A-Gchr13-32363234-A-T

Variant summary

Our verdict is Uncertain significance. Variant got 4 ACMG points: 4P and 0B. PM1 PM2

The NM_000059.4(BRCA2):c.8032A>G(p.Arg2678Gly) variant causes a missense change. The variant allele was found at a frequency of 0.000000684 in 1,461,724 control chromosomes in the GnomAD database, with no homozygous occurrence. 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. R2678K) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: BRCA2 NM_000059.4 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:6 B:1
• Conservation: PhyloP100: 6.92

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 4 ACMG points.

• PM1: In a hotspot region, there are 4 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 5 benign, 16 uncertain in NM_000059.4
• PM2: Very rare variant in population databases, with high coverage

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
BRCA2	NM_000059.4	c.8032A>G	p.Arg2678Gly	missense_variant	18/27	ENST00000380152.8

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
BRCA2	ENST00000380152.8	c.8032A>G	p.Arg2678Gly	missense_variant	18/27	5	NM_000059.4	A2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461724 Hom.: 0 Cov.: 31 AF XY: 0.00000138 AC XY: 1 AN XY: 727146

Gnomad4 AFR exome AF: 0.0000299

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:6 Benign:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

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

Uncertain significance, criteria provided, single submitter	clinical testing	Counsyl	Mar 22, 2018	- -
Uncertain significance, no assertion criteria provided	clinical testing	Breast Cancer Information Core (BIC) (BRCA2)	Feb 20, 2004	- -
Uncertain significance, no assertion criteria provided	clinical testing	Sharing Clinical Reports Project (SCRP)	Jun 29, 2009	- -

not specified Uncertain:1

Uncertain significance, no assertion criteria provided

research

Research Molecular Genetics Laboratory, Women's College Hospital, University of Toronto

Jan 31, 2014

- -

not provided Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

GeneDx

Oct 02, 2019

Not observed in large population cohorts (Lek 2016); In silico analysis, which includes protein predictors and evolutionary conservation, supports that this variant does not alter protein structure/function; Observed in an individual with early onset breast cancer (Lee 2008); Also known as BRCA2 8260A>G; This variant is associated with the following publications: (PMID: 29884841, 31131967, 18284688, 19043619, 29394989, 20127978) -

Hereditary breast ovarian cancer syndrome Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

May 14, 2023

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. Experimental studies have shown that this missense change does not substantially affect BRCA2 function (PMID: 29394989). Advanced modeling performed at Invitae incorporating data from internal and/or published experimental studies (PMID: 33609447) indicates that this missense variant is not expected to disrupt BRCA2 function. ClinVar contains an entry for this variant (Variation ID: 52478). This missense change has been observed in individual(s) with clinical features of BRCA2-related conditions (PMID: 20127978). This variant is not present in population databases (gnomAD no frequency). This sequence change replaces arginine, which is basic and polar, with glycine, which is neutral and non-polar, at codon 2678 of the BRCA2 protein (p.Arg2678Gly). -

Hereditary cancer-predisposing syndrome Benign:1

Likely benign, criteria provided, single submitter

clinical testing

Ambry Genetics

Dec 06, 2019

This alteration is classified as likely benign based on a combination of the following: seen in unaffected individuals, population frequency, intact protein function, lack of segregation with disease, co-occurrence, RNA analysis, in silico models, amino acid conservation, lack of disease association in case-control studies, and/or the mechanism of disease or impacted region is inconsistent with a known cause of pathogenicity. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Uncertain	0.34
BayesDel_addAF	Pathogenic	0.20	D
BayesDel_noAF	Uncertain	0.050
Cadd	Uncertain	25
Dann	Uncertain	1.0
Eigen	Uncertain	0.63
Eigen_PC	Uncertain	0.62
FATHMM_MKL	Pathogenic	0.99	D
M_CAP	Uncertain	0.23	D
MetaRNN	Uncertain	0.55	D;D
MetaSVM	Uncertain	0.057	D
MutationTaster	Benign	1.0	D;D
PrimateAI	Benign	0.42	T
PROVEAN	Benign	-2.1	N;N
REVEL	Pathogenic	0.66
Sift	Uncertain	0.0010	D;D
Sift4G	Uncertain	0.0030	D;D
Vest4		0.46
MutPred		0.54		Gain of relative solvent accessibility (P = 0.0166);Gain of relative solvent accessibility (P = 0.0166);
MVP		0.92
MPC		0.16
ClinPred		0.98	D
GERP RS		5.1
gMVP		0.51

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: rs80359039; hg19: chr13-32937371;