13-32370526-A-T

Variant names:

• chr13-32370526-A-T
• rs1555287655
• NM_000059.4:c.8456A>T

Variant summary

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

The NM_000059.4(BRCA2):​c.8456A>T​(p.Asp2819Val) variant causes a missense change involving the alteration of a conserved nucleotide. 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:2
• Conservation: PhyloP100: 9.25

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, 0.848

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
BRCA2	NM_000059.4	c.8456A>T	p.Asp2819Val	missense_variant	Exon 19 of 27	ENST00000380152.8	NP_000050.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
BRCA2	ENST00000380152.8	c.8456A>T	p.Asp2819Val	missense_variant	Exon 19 of 27	5	NM_000059.4	ENSP00000369497.3
BRCA2	ENST00000530893.7	c.8087A>T	p.Asp2696Val	missense_variant	Exon 19 of 27	1		ENSP00000499438.2
BRCA2	ENST00000614259.2	n.*514A>T		non_coding_transcript_exon_variant	Exon 18 of 26	2		ENSP00000506251.1
BRCA2	ENST00000614259	n.*514A>T		3_prime_UTR_variant	Exon 18 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:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Hereditary cancer-predisposing syndrome Uncertain:1

Jan 11, 2022

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The p.D2819V variant (also known as c.8456A>T), located in coding exon 18 of the BRCA2 gene, results from an A to T substitution at nucleotide position 8456. The aspartic acid at codon 2819 is replaced by valine, an amino acid with highly dissimilar properties. This alteration was seen in 1/732 breast cancer patients, 0/189 colorectal cancer patients and 0/490 cancer-free elderly controls in a Turkish population (Akcay IM et al. Int J Cancer, 2021 01;148(2):285-295). This variant has also been reported as non-functional in homology-directed DNA repair (HDR) assays (Richardson ME et al. Am J Hum Genet, 2021 03;108:458-468 and Ambry internal data). This amino acid position is highly conserved in available vertebrate species. In addition, this alteration is predicted to be deleterious 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

Oct 08, 2019

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant is not present in population databases (ExAC no frequency). This sequence change replaces aspartic acid with valine at codon 2819 of the BRCA2 protein (p.Asp2819Val). The aspartic acid residue is highly conserved and there is a large physicochemical difference between aspartic acid and valine. This variant has not been reported in the literature in individuals with BRCA2-related conditions. ClinVar contains an entry for this variant (Variation ID: 481554). 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. Algorithms developed to predict the effect of missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be disruptive, but these predictions have not been confirmed by published functional studies and their clinical significance is uncertain. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.68
BayesDel_addAF	Pathogenic	0.40	D
BayesDel_noAF	Pathogenic	0.33
CADD	Pathogenic	26
DANN	Uncertain	0.99
Eigen	Uncertain	0.63
Eigen_PC	Uncertain	0.55
FATHMM_MKL	Pathogenic	0.99	D
M_CAP	Pathogenic	0.31	D
MetaRNN	Pathogenic	0.85	D;D
MetaSVM	Uncertain	0.19	D
PrimateAI	Uncertain	0.56	T
PROVEAN	Uncertain	-2.4	N;N
REVEL	Uncertain	0.62
Sift	Pathogenic	0.0	D;D
Sift4G	Pathogenic	0.0	D;D
Vest4		0.80
MutPred		0.47		Gain of sheet (P = 0.1451);Gain of sheet (P = 0.1451);
MVP		0.94
MPC		0.18
ClinPred		0.99	D
GERP RS		5.2
gMVP		0.84

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		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: rs1555287655; hg19: chr13-32944663; COSMIC: COSV66460655; COSMIC: COSV66460655;