chr13-32363391-C-G

Variant names:

• chr13-32363391-C-G
• rs80359067
• NM_000059.4:c.8189C>G

Variant summary

Our verdict is Uncertain significance. Variant got 4 ACMG points: 4P and 0B. PM2 PP3_Moderate

The NM_000059.4(BRCA2):​c.8189C>G​(p.Ala2730Gly) variant causes a missense change. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic 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:3
• Conservation: PhyloP100: 3.81

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.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.861

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
BRCA2	NM_000059.4	c.8189C>G	p.Ala2730Gly	missense_variant	Exon 18 of 27	ENST00000380152.8	NP_000050.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
BRCA2	ENST00000380152.8	c.8189C>G	p.Ala2730Gly	missense_variant	Exon 18 of 27	5	NM_000059.4	ENSP00000369497.3
BRCA2	ENST00000530893.7	c.7820C>G	p.Ala2607Gly	missense_variant	Exon 18 of 27	1		ENSP00000499438.2
BRCA2	ENST00000614259.2	n.*247C>G		non_coding_transcript_exon_variant	Exon 17 of 26	2		ENSP00000506251.1
BRCA2	ENST00000614259	n.*247C>G		3_prime_UTR_variant	Exon 17 of 25	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

Malignant tumor of breast Uncertain:1

-

Department of Pathology and Laboratory Medicine, Sinai Health System

Significance: Uncertain significance

Review Status: no assertion criteria provided

Collection Method: clinical testing

The BRCA2 p.Ala2730Gly variant was not identified in the literature nor was it identified in dbSNP ClinVar, UMD-LSDB, Exome Aggregation Consortium (August 8th 2016) and the Genome Aggregation Database (Feb 27, 2017). The variant was identified in LOVD 3.0 (observed 1x). The p.Ala2730 residue is conserved in mammals and computational analyses (PolyPhen-2, SIFT, AlignGVGD, BLOSUM, MutationTaster) provide inconsistent predictions regarding the impact to the protein; this information is not very predictive of pathogenicity. The variant occurs outside of the splicing consensus sequence and 1 of 4 in silico or computational prediction software programs (SpliceSiteFinder, MaxEntScan, NNSPLICE, GeneSplicer) predict a greater than 10% difference in splicing; this 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 cancer-predisposing syndrome Uncertain:1

Jun 19, 2023

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The p.A2730G variant (also known as c.8189C>G), located in coding exon 17 of the BRCA2 gene, results from a C to G substitution at nucleotide position 8189. The alanine at codon 2730 is replaced by glycine, an amino acid with similar properties. This variant was observed in 1/3251 individuals who met eligibility criteria for hereditary breast and ovarian cancer syndrome (Lerner-Ellis J et al. J Cancer Res Clin Oncol, 2021 Mar;147:871-879). This amino acid position is highly 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. -

Hereditary breast ovarian cancer syndrome Uncertain:1

Oct 30, 2022

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

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. ClinVar contains an entry for this variant (Variation ID: 661444). This sequence change replaces alanine, which is neutral and non-polar, with glycine, which is neutral and non-polar, at codon 2730 of the BRCA2 protein (p.Ala2730Gly). 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. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.13
BayesDel_addAF	Pathogenic	0.24	D
BayesDel_noAF	Uncertain	0.10
CADD	Benign	23
DANN	Uncertain	1.0
Eigen	Uncertain	0.64
Eigen_PC	Uncertain	0.58
FATHMM_MKL	Pathogenic	0.97	D
M_CAP	Uncertain	0.14	D
MetaRNN	Pathogenic	0.86	D;D
MetaSVM	Uncertain	0.57	D
PrimateAI	Benign	0.42	T
PROVEAN	Benign	-1.2	N;N
REVEL	Uncertain	0.61
Sift	Uncertain	0.0040	D;D
Sift4G	Uncertain	0.013	D;D
Vest4		0.48
MutPred		0.71		Gain of relative solvent accessibility (P = 0.0082);Gain of relative solvent accessibility (P = 0.0082);
MVP		0.94
MPC		0.082
ClinPred		0.97	D
GERP RS		5.5
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
gMVP		0.72

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: rs80359067; hg19: chr13-32937528;