13-32338163-G-A

Position:

• chr13-32338163-G-A

Variant summary

Our verdict is Likely benign. Variant got -2 ACMG points: 0P and 2B. BP4_Moderate

The NM_000059.4(BRCA2):​c.3808G>A​(p.Val1270Ile) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000418 in 1,435,974 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). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. V1270A) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0000042 (0 hom.)
• Consequence: BRCA2 NM_000059.4 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:3 B:1
• Conservation: PhyloP100: 2.31

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 -2 ACMG points.

• BP4: Computational evidence support a benign effect (MetaRNN=0.1387038).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
BRCA2	NM_000059.4	c.3808G>A	p.Val1270Ile	missense_variant	11/27	ENST00000380152.8

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
BRCA2	ENST00000380152.8	c.3808G>A	p.Val1270Ile	missense_variant	11/27	5	NM_000059.4	A2

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 0.00000418 AC: 6 AN: 1435974 Hom.: 0 Cov.: 34 AF XY: 0.00000421 AC XY: 3 AN XY: 713200

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: 0.00000364

Gnomad4 OTH exome AF: 0.0000337

GnomAD4 genome Cov.: 33

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:3 Benign:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Hereditary cancer-predisposing syndrome Uncertain:1 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). -
Uncertain significance, criteria provided, single submitter	clinical testing	Ambry Genetics	Jul 23, 2020	The p.V1270I variant (also known as c.3808G>A), located in coding exon 10 of the BRCA2 gene, results from a G to A substitution at nucleotide position 3808. The valine at codon 1270 is replaced by isoleucine, an amino acid with highly similar properties. In one study, this alteration was not detected in a cohort of 7051 unselected female breast cancer patients but was observed in 1/11241 female controls of Japanese ancestry (Momozawa Y et al. Nat Commun, 2018 10;9:4083). This amino acid position is not well conserved in available vertebrate species. In addition, this alteration is predicted to be tolerated by in silico analysis. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -

Medulloblastoma;C0346153:Familial cancer of breast;C0376358:Malignant tumor of prostate;C1838457:Fanconi anemia complementation group D1;C2675520:Breast-ovarian cancer, familial, susceptibility to, 2;C2751641:Glioma susceptibility 3;C3150546:Pancreatic cancer, susceptibility to, 2;CN033288:Wilms tumor 1 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Fulgent Genetics, Fulgent Genetics

Oct 31, 2018

- -

not provided Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

GeneDx

Oct 19, 2020

Not observed in large population cohorts (Lek 2016); In silico analysis supports that this missense variant does not alter protein structure/function; Has not been previously published as pathogenic or benign to our knowledge; Also known as c.4036G>A; This variant is associated with the following publications: (PMID: 30287823) -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.10
BayesDel_addAF	Benign	-0.12	T
BayesDel_noAF	Benign	-0.41
CADD	Benign	9.8
DANN	Benign	0.97
Eigen	Benign	-0.46
Eigen_PC	Benign	-0.50
FATHMM_MKL	Benign	0.26	N
M_CAP	Benign	0.015	T
MetaRNN	Benign	0.14	T;T
MetaSVM	Benign	-1.0	T
MutationTaster	Benign	1.0	N;N
PrimateAI	Benign	0.32	T
PROVEAN	Benign	-0.73	N;N
REVEL	Benign	0.13
Sift	Benign	0.054	T;T
Sift4G	Benign	0.12	T;T
Vest4		0.25
MutPred		0.19		Loss of sheet (P = 0.1501);Loss of sheet (P = 0.1501);
MVP		0.63
MPC		0.033
ClinPred		0.20	T
GERP RS		4.4
gMVP		0.096

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: rs876658938; hg19: chr13-32912300;