13-32344617-G-A

Position:

• chr13-32344617-G-A

Variant summary

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

The NM_000059.4(BRCA2):​c.6901G>A​(p.Glu2301Lys) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000014 in 1,431,184 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 Uncertain significance (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. E2301G) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: BRCA2 NM_000059.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:2
• Conservation: PhyloP100: 1.16

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.6901G>A	p.Glu2301Lys	missense_variant	12/27	ENST00000380152.8

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
BRCA2	ENST00000380152.8	c.6901G>A	p.Glu2301Lys	missense_variant	12/27	5	NM_000059.4	A2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000140 AC: 2 AN: 1431184 Hom.: 0 Cov.: 29 AF XY: 0.00000140 AC XY: 1 AN XY: 713676

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: 0.00000184

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, single submitter

Submissions by phenotype

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

Uncertain significance, no assertion criteria provided

clinical testing

Breast Cancer Information Core (BIC) (BRCA2)

Mar 30, 2004

- -

Hereditary cancer-predisposing syndrome Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Oct 14, 2021

The c.6901G>A variant (also known as p.E2301K), located in coding exon 11 of the BRCA2 gene, results from a G to A substitution at nucleotide position 6901. The glutamic acid at codon 2301 is replaced by lysine, an amino acid with similar properties. In a study of 1854 high-risk breast and ovarian cancer families in Italy, this alteration was detected in 1 family (Azzollini J et al. Eur J Intern Med, 2016 Jul;32:65-71). This nucleotide position is well conserved in available vertebrate species. In silico splice site analysis predicts that this alteration may weaken the native splice donor site; however this exon may be clinically dispensable based on partially retained homology directed DNA repair activity (Meulemans L et al. Cancer Res, 2020 04;80:1374-1386). In addition, the literature describes a patient with a splice variant causing coding exon 11 skipping found in trans with a truncating BRCA2 variant in an individual without apparent Fanconi Anemia; although the degree of exon skipping is uncertain (Li L et al. Hum. Mutat., 2009 Nov;30:1543-50; Meulemans L et al. Cancer Res, 2020 04;80:1374-1386). Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.085
BayesDel_addAF	Uncertain	0.027	T
BayesDel_noAF	Benign	-0.20
CADD	Benign	19
DANN	Uncertain	0.99
Eigen	Benign	-0.24
Eigen_PC	Benign	-0.11
FATHMM_MKL	Benign	0.47	N
M_CAP	Benign	0.084	D
MetaRNN	Benign	0.16	T;T
MetaSVM	Benign	-0.84	T
MutationTaster	Benign	1.0	N;N
PrimateAI	Benign	0.26	T
PROVEAN	Benign	-0.60	N;N
REVEL	Uncertain	0.35
Sift	Benign	0.21	T;T
Sift4G	Benign	0.66	T;T
Vest4		0.26
MutPred		0.21		Gain of MoRF binding (P = 0.0065);Gain of MoRF binding (P = 0.0065);
MVP		0.88
MPC		0.13
ClinPred		0.76	D
GERP RS		3.2
gMVP		0.11

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.39		Details are displayed if max score is > 0.2
DS_DL_spliceai		0.39		Position offset: 36

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

LitVar

Other links and lift over

dbSNP: rs80358915; hg19: chr13-32918754;