13-32357798-G-C

Position:

• chr13-32357798-G-C

Variant summary

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

The NM_000059.4(BRCA2):​c.7674G>C​(p.Glu2558Asp) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. 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:3
• Conservation: PhyloP100: 0.631

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]

BRCA2 (HGNC:):

ACMG classification

Verdict is Uncertain_significance. Variant got 2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
BRCA2	NM_000059.4	c.7674G>C	p.Glu2558Asp	missense_variant	16/27	ENST00000380152.8	NP_000050.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
BRCA2	ENST00000380152.8	c.7674G>C	p.Glu2558Asp	missense_variant	16/27	5	NM_000059.4	ENSP00000369497.3
BRCA2	ENST00000530893.7	c.7305G>C	p.Glu2435Asp	missense_variant	16/27	1		ENSP00000499438.2
BRCA2	ENST00000614259.2	n.7674G>C		non_coding_transcript_exon_variant	15/26	2		ENSP00000506251.1

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

Feb 08, 2017

This variant is denoted BRCA2 c.7674G>C at the cDNA level, p.Glu2558Asp (E2558D) at the protein level, and results in the change of a Glutamic Acid to an Aspartic Acid (GAG>GAC). Using alternate nomenclature, this variant would be defined as BRCA2 7902G>C. This variant has not, to our knowledge, been published in the literature as pathogenic or benign. BRCA2 Glu2558Asp 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 Aspartic Acid share similar properties, this is considered a conservative amino acid substitution. BRCA2 Glu2558Asp occurs at a position that is not conserved and is located in the DNA binding domain (Yang 2002). 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 Glu2558Asp is a pathogenic or benign variant. We consider it to be a variant of uncertain significance. -

Malignant tumor of breast Uncertain:1

Uncertain significance, no assertion criteria provided

clinical testing

Department of Pathology and Laboratory Medicine, Sinai Health System

-

The BRCA2 p.Glu2558Asp variant was identified in dbSNP (ID: rs730881558) as “Uncertain significance”, the ClinVar database (as uncertain significance, by GeneDx), and the Clinvitae database (as uncertain significance from ClinVar). The variant was not identified in the 1000 Genomes Project, NHLBI GO Exome Sequencing Project, the Exome Aggregation Consortium database (August 8, 2016), LOVD-IARC database, ARUP Laboratories BRCA Mutations Database, COSMIC, GeneInsight-COGR database, the BIC database, Fanconi Anemia Mutation Database (LOVD), and UMD. The p.Glu2558 residue is conserved in mammals but not more distantly related organisms and four out of five computational analyses (PolyPhen-2, SIFT, AlignGVGD, BLOSUM, MutationTaster) do not suggest a high likelihood of impact to the protein; however, this information is not predictive enough to rule out pathogenicity. The variant occurs outside of the splicing consensus sequence and 1 of 5 in silico or computational prediction software programs (SpliceSiteFinder, MaxEntScan, NNSPLICE, GeneSplicer, HumanSpliceFinder) predicts the creation of a 3’ splice site, however this information is not very predictive of pathogenicity. In summary, based on the above information, the clinical significance of this variant cannot be determined with certainty at this time. This variant is classified as a variant of uncertain significance. -

Hereditary breast ovarian cancer syndrome Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Jul 09, 2023

ClinVar contains an entry for this variant (Variation ID: 182242). 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. 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. This variant has not been reported in the literature in individuals affected with BRCA2-related conditions. This sequence change replaces glutamic acid, which is acidic and polar, with aspartic acid, which is acidic and polar, at codon 2558 of the BRCA2 protein (p.Glu2558Asp). This variant is not present in population databases (gnomAD no frequency). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Uncertain	0.38
BayesDel_addAF	Pathogenic	0.20	D
BayesDel_noAF	Uncertain	0.040
CADD	Benign	21
DANN	Uncertain	0.99
Eigen	Benign	0.15
Eigen_PC	Benign	0.11
FATHMM_MKL	Uncertain	0.89	D
M_CAP	Benign	0.083	D
MetaRNN	Uncertain	0.51	D;D
MetaSVM	Uncertain	-0.052	T
PrimateAI	Benign	0.46	T
PROVEAN	Benign	-0.76	N;N
REVEL	Uncertain	0.58
Sift	Uncertain	0.019	D;D
Sift4G	Benign	0.21	T;T
Vest4		0.62
MutPred		0.52		Gain of loop (P = 0.0851);Gain of loop (P = 0.0851);
MVP		0.92
MPC		0.072
ClinPred		0.79	D
GERP RS		1.5
gMVP		0.53

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.060		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: rs730881558; hg19: chr13-32931935;