chr13-32337432-A-C

Position:

• chr13-32337432-A-C

Variant summary

Our verdict is Uncertain significance. Variant got 2 ACMG points: 3P and 1B. PM2 PP3 BP6

The NM_000059.4(BRCA2):​c.3077A>C​(p.Lys1026Thr) variant causes a missense change involving the alteration of a non-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 Conflicting classifications of pathogenicity (no stars).

• Frequency: Genomes: not found (cov: 32)
• Consequence: BRCA2 NM_000059.4 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:1 B:1
• Conservation: PhyloP100: 3.15

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
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.77
• BP6: Variant 13-32337432-A-C is Benign according to our data. Variant chr13-32337432-A-C is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 1062832.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.3077A>C	p.Lys1026Thr	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.3077A>C	p.Lys1026Thr	missense_variant	11/27	5	NM_000059.4	ENSP00000369497	A2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 33

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

Sep 13, 2020

This sequence change replaces lysine with threonine at codon 1026 of the BRCA2 protein (p.Lys1026Thr). The lysine residue is moderately conserved and there is a moderate physicochemical difference between lysine and threonine. This variant is not present in population databases (ExAC no frequency). This variant has not been reported in the literature in individuals with BRCA2-related conditions. 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. -

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	Uncertain	0.43
BayesDel_addAF	Pathogenic	0.25	D
BayesDel_noAF	Uncertain	0.12
CADD	Uncertain	24
DANN	Uncertain	1.0
Eigen	Uncertain	0.53
Eigen_PC	Uncertain	0.54
FATHMM_MKL	Uncertain	0.92	D
M_CAP	Uncertain	0.25	D
MetaRNN	Pathogenic	0.77	D;D
MetaSVM	Uncertain	0.63	D
MutationTaster	Benign	0.95	D;D
PrimateAI	Uncertain	0.51	T
PROVEAN	Pathogenic	-5.4	D;D
REVEL	Pathogenic	0.67
Sift	Uncertain	0.0010	D;D
Sift4G	Uncertain	0.0060	D;D
Vest4		0.48
MutPred		0.74		Loss of methylation at K1026 (P = 0.0268);Loss of methylation at K1026 (P = 0.0268);
MVP		0.97
MPC		0.17
ClinPred		0.99	D
GERP RS		4.9
gMVP		0.56

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

No publications associated with this variant yet.

Other links and lift over

hg19: chr13-32911569;