13-32338721-G-A

Position:

• chr13-32338721-G-A

Variant summary

Our verdict is Uncertain significance. Variant got 1 ACMG points: 2P and 1B. PM2 BP4

The NM_000059.4(BRCA2):​c.4366G>A​(p.Glu1456Lys) variant causes a missense change. The variant allele was found at a frequency of 0.000000692 in 1,445,770 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 6.9e-7 (0 hom.)
• Consequence: BRCA2 NM_000059.4 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:4 B:1
• Conservation: PhyloP100: 4.51

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 1 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.34591368).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
BRCA2	NM_000059.4	c.4366G>A	p.Glu1456Lys	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.4366G>A	p.Glu1456Lys	missense_variant	11/27	5	NM_000059.4	ENSP00000369497	A2

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD3 exomes AF: 0.00000411 AC: 1 AN: 243456 Hom.: 0 AF XY: 0.00000758 AC XY: 1 AN XY: 131914

Gnomad AFR exome AF: 0.0000645

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 6.92e-7 AC: 1 AN: 1445770 Hom.: 0 Cov.: 35 AF XY: 0.00000140 AC XY: 1 AN XY: 716156

Gnomad4 AFR exome AF: 0.0000303

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: 0.00

GnomAD4 genome Cov.: 33

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:4 Benign:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Hereditary cancer-predisposing syndrome Uncertain:1 Benign:1

Uncertain significance, criteria provided, single submitter	clinical testing	Ambry Genetics	May 25, 2023	The p.E1456K variant (also known as c.4366G>A), located in coding exon 10 of the BRCA2 gene, results from a G to A substitution at nucleotide position 4366. The glutamic acid at codon 1456 is replaced by lysine, an amino acid with similar properties. In a study of unselected Japanese breast cancer patients, this alteration was detected in 1/12490 male controls but not detected in 7051 breast cancer patients or in 11241 female controls (Momozawa Y et al. Nat Commun, 2018 10;9:4083). This alteration was also detected in a cohort of 1663 Brazilian breast cancer patients who underwent hereditary multigene panel testing (Guindalini RSC et al. Sci Rep, 2022 Mar;12:4190). This amino acid position is well 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. -
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). -

Breast-ovarian cancer, familial, susceptibility to, 2 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Mendelics

May 28, 2019

- -

not provided Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

GeneDx

Sep 04, 2015

This variant is denoted BRCA2 c.4366G>A at the cDNA level, p.Glu1456Lys (E1456K) at the protein level, and results in the change of a Glutamic Acid to a Lysine (GAA>AAA). Using alternate nomenclature, this variant would be defined as BRCA2 4594G>A. This variant has not, to our knowledge, been published in the literature as pathogenic or benign. BRCA2 Glu1456Lys was not observed in approximately 6,500 individuals of European and African American ancestry in the NHLBI Exome Sequencing Project, indicating it is not a common benign variant in these populations. Since Glutamic Acid and Lysine differ in polarity, charge, size or other properties, this is considered a non-conservative amino acid substitution. BRCA2 Glu1456Lys occurs at a position that is not conserved and is located in a region of interaction with POLH and required for stimulation of POLH DNA polymerization activity (UniProt). In silico analyses are inconsistent regarding the effect this variant may have on protein structure and function. Based on currently available information, it is unclear whether BRCA2 Glu1456Lys is pathogenic or benign. We consider it to be a variant of uncertain significance. -

Hereditary breast ovarian cancer syndrome Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Jan 19, 2024

This sequence change replaces glutamic acid, which is acidic and polar, with lysine, which is basic and polar, at codon 1456 of the BRCA2 protein (p.Glu1456Lys). This variant is present in population databases (no rsID available, gnomAD 0.007%). This missense change has been observed in individual(s) with breast cancer (PMID: 35264596). ClinVar contains an entry for this variant (Variation ID: 232573). 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 with a negative predictive value of 95%. 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. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.11
BayesDel_addAF	Benign	-0.082	T
BayesDel_noAF	Benign	-0.17
CADD	Uncertain	24
DANN	Uncertain	1.0
Eigen	Uncertain	0.23
Eigen_PC	Uncertain	0.29
FATHMM_MKL	Uncertain	0.93	D
M_CAP	Uncertain	0.16	D
MetaRNN	Benign	0.35	T;T
MetaSVM	Benign	-0.54	T
MutationTaster	Benign	0.95	D;D
PrimateAI	Benign	0.38	T
PROVEAN	Uncertain	-3.3	D;D
REVEL	Benign	0.12
Sift	Uncertain	0.0020	D;D
Sift4G	Uncertain	0.025	D;D
Vest4		0.41
MutPred		0.26		Gain of ubiquitination at E1456 (P = 0.0114);Gain of ubiquitination at E1456 (P = 0.0114);
MVP		0.88
MPC		0.11
ClinPred		0.86	D
GERP RS		4.8
gMVP		0.40

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: rs876659847; hg19: chr13-32912858;