rs1064795880

chr13-32398439-A-Gchr13-32398439-A-T

Variant summary

Our verdict is Uncertain significance. Variant got 0 ACMG points: 2P and 2B. PM2 BP4_Moderate

The NM_000059.4(BRCA2):c.9926A>G(p.Glu3309Gly) 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 Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. E3309K) has been classified as Likely benign.

• Frequency: Genomes: not found (cov: 32)
• Consequence: BRCA2 NM_000059.4 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:3
• Conservation: PhyloP100: 0.455

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 0 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.10244349).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
BRCA2	NM_000059.4	c.9926A>G	p.Glu3309Gly	missense_variant	27/27	ENST00000380152.8

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
BRCA2	ENST00000380152.8	c.9926A>G	p.Glu3309Gly	missense_variant	27/27	5	NM_000059.4	A2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:3

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not provided Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

GeneDx

Oct 21, 2016

This variant is denoted BRCA2 c.9926A>G at the cDNA level, p.Glu3309Gly (E3309G) at the protein level, and results in the change of a Glutamic Acid to a Glycine (GAA>GGA). Using alternate nomenclature, this variant would be defined as BRCA2 10154A>G. This variant has not, to our knowledge, been published in the literature as pathogenic or benign. BRCA2 Glu3309Gly was not observed in approximately 6,500 individuals of European and African American ancestry in the NHLBI Exome Sequencing Project, suggesting it is not a common benign variant in these populations. Since Glutamic Acid and Glycine differ in polarity, charge, size or other properties, this is considered a non-conservative amino acid substitution. BRCA2 Glu3309Gly occurs at a position that is not conserved and is not located in a known functional domain. In silico analyses are inconsistent regarding the effect this variant may have on protein structure and function. Based on currently available evidence, it is unclear whether BRCA2 Glu3309Gly is a pathogenic or benign variant. We consider it to be a variant of uncertain significance. -

Hereditary cancer-predisposing syndrome Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Jun 28, 2021

The p.E3309G variant (also known as c.9926A>G), located in coding exon 26 of the BRCA2 gene, results from an A to G substitution at nucleotide position 9926. The glutamic acid at codon 3309 is replaced by glycine, an amino acid with similar properties. This amino acid position is conserved. In addition, this alteration is predicted to be tolerated by in silico analysis. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -

Hereditary breast ovarian cancer syndrome Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Feb 18, 2022

This variant has not been reported in the literature in individuals affected with BRCA2-related conditions. This variant is not present in population databases (gnomAD no frequency). This sequence change replaces glutamic acid, which is acidic and polar, with glycine, which is neutral and non-polar, at codon 3309 of the BRCA2 protein (p.Glu3309Gly). ClinVar contains an entry for this variant (Variation ID: 422594). 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. 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. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.10
BayesDel_addAF	Benign	-0.20	T
BayesDel_noAF	Benign	-0.52
Cadd	Benign	18
Dann	Uncertain	1.0
Eigen	Benign	-0.77
Eigen_PC	Benign	-0.80
FATHMM_MKL	Benign	0.032	N
M_CAP	Uncertain	0.14	D
MetaRNN	Benign	0.10	T;T
MetaSVM	Benign	-0.90	T
MutationTaster	Benign	1.0	N;N
PrimateAI	Benign	0.26	T
PROVEAN	Benign	-1.4	N;N
REVEL	Benign	0.058
Sift	Benign	0.30	T;T
Sift4G	Benign	0.34	T;T
Vest4		0.16
MutPred		0.10		Loss of ubiquitination at K3313 (P = 0.0261);Loss of ubiquitination at K3313 (P = 0.0261);
MVP		0.72
MPC		0.17
ClinPred		0.34	T
GERP RS		-0.73
gMVP		0.21

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.020		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: rs1064795880; hg19: chr13-32972576;