rs397507878

chr13-32329482-A-Cchr13-32329482-A-T

Variant summary

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

The NM_000059.4(BRCA2):c.671A>C(p.Asp224Ala) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. 11/19 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. D224N) has been classified 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: 1.82

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 2 ACMG points.

• 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.671A>C	p.Asp224Ala	missense_variant	8/27	ENST00000380152.8

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
BRCA2	ENST00000380152.8	c.671A>C	p.Asp224Ala	missense_variant	8/27	5	NM_000059.4	A2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 28

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

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Nov 13, 2013

​The p.D224A variant (also known as c.671A>C or 899A>C) is located in coding exon 7 of the BRCA2 gene. This alteration results from an A to C substitution at nucleotide position 671. The aspartic acid at codon 224 is replaced by alanine, an amino acid with dissimilar properties. This variant was not reported in population-based cohorts in the following databases: Database of Single Nucleotide Polymorphisms (dbSNP), NHLBI Exome Sequencing Project (ESP) and 1000 Genomes Project. Another amino acid substitution at this position (p.D224V) was described in a family with three cases of female breast cancer and one case of male breast cancer (Evans DG et al. Fam. Cancer 2008;7(2):113-7). Based on protein sequence alignment, this amino acid position is highly conserved in available vertebrate species. In addition, this alteration is predicted to be possibly damaging and deleterious by PolyPhen and SIFT in silico analyses, respectively. Since supporting evidence is limited at this time, the clinical significance of p.D224A remains unclear. -

Hereditary breast ovarian cancer syndrome Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Sep 20, 2019

This variant is not present in population databases (ExAC no frequency). 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 tolerated, but these predictions have not been confirmed by published functional studies and their clinical significance is uncertain. This variant has not been reported in the literature in individuals with BRCA2-related conditions. ClinVar contains an entry for this variant (Variation ID: 141017). This sequence change replaces aspartic acid with alanine at codon 224 of the BRCA2 protein (p.Asp224Ala). The aspartic acid residue is moderately conserved and there is a moderate physicochemical difference between aspartic acid and alanine. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.16
BayesDel_addAF	Benign	0.0071	T
BayesDel_noAF	Benign	-0.23
Cadd	Benign	21
Dann	Uncertain	0.99
Eigen	Uncertain	0.30
Eigen_PC	Uncertain	0.25
FATHMM_MKL	Benign	0.27	N
M_CAP	Benign	0.034	D
MetaRNN	Uncertain	0.61	D;D
MetaSVM	Benign	-1.1	T
MutationTaster	Benign	0.57	N;N
PrimateAI	Benign	0.44	T
PROVEAN	Benign	-1.7	N;N
REVEL	Benign	0.13
Sift	Uncertain	0.0030	D;D
Sift4G	Benign	0.093	T;T
Vest4		0.55
MutPred		0.44		Loss of disorder (P = 0.1041);Loss of disorder (P = 0.1041);
MVP		0.91
MPC		0.022
ClinPred		0.85	D
GERP RS		4.4
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.2
gMVP		0.43

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: rs397507878; hg19: chr13-32903619;