chr13-32336877-G-C

Position:

• chr13-32336877-G-C

Variant summary

Our verdict is Likely benign. Variant got -3 ACMG points: 2P and 5B. PM2 BP4_Strong BP6

The NM_000059.4(BRCA2):​c.2522G>C​(p.Arg841Thr) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000686 in 1,458,546 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 14/19 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.9e-7 (0 hom.)
• Consequence: BRCA2 NM_000059.4 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:1 B:1
• Conservation: PhyloP100: -0.640

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 Likely_benign. Variant got -3 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.04186225).
• BP6: Variant 13-32336877-G-C is Benign according to our data. Variant chr13-32336877-G-C is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 462267.We mark this variant Likely_benign, oryginal submissions are: {Likely_benign=1, Uncertain_significance=1}.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
BRCA2	NM_000059.4	c.2522G>C	p.Arg841Thr	missense_variant	11/27	ENST00000380152.8	NP_000050.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
BRCA2	ENST00000380152.8	c.2522G>C	p.Arg841Thr	missense_variant	11/27	5	NM_000059.4	ENSP00000369497	A2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.86e-7 AC: 1 AN: 1458546 Hom.: 0 Cov.: 33 AF XY: 0.00000138 AC XY: 1 AN XY: 725322

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00

Gnomad4 OTH exome AF: 0.0000166

GnomAD4 genome Cov.: 32

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:1 Benign:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Hereditary breast ovarian cancer syndrome Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Feb 08, 2023

ClinVar contains an entry for this variant (Variation ID: 462267). 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 arginine, which is basic and polar, with threonine, which is neutral and polar, at codon 841 of the BRCA2 protein (p.Arg841Thr). This variant is not present in population databases (gnomAD no frequency). -

Hereditary cancer-predisposing syndrome Benign:1

Likely benign, criteria provided, single submitter

curation

University of Washington Department of Laboratory Medicine, University of Washington

Mar 23, 2023

Missense variant in a coldspot region where missense variants are very unlikely to be pathogenic (PMID:31911673). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.053
BayesDel_addAF	Benign	-0.24	T
BayesDel_noAF	Benign	-0.58
CADD	Benign	0.015
DANN	Benign	0.071
Eigen	Benign	-1.8
Eigen_PC	Benign	-1.8
FATHMM_MKL	Benign	0.017	N
M_CAP	Benign	0.0060	T
MetaRNN	Benign	0.042	T;T
MetaSVM	Benign	-1.1	T
MutationTaster	Benign	1.0	N;N
PrimateAI	Benign	0.23	T
PROVEAN	Benign	2.3	N;N
REVEL	Benign	0.041
Sift	Benign	1.0	T;T
Sift4G	Benign	0.50	T;T
Vest4		0.11
MutPred		0.33		Loss of MoRF binding (P = 0.0132);Loss of MoRF binding (P = 0.0132);
MVP		0.65
MPC		0.022
ClinPred		0.048	T
GERP RS		-5.1
gMVP		0.14

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: rs587781915; hg19: chr13-32911014;