chr13-32332737-A-G

Position:

• chr13-32332737-A-G

Variant summary

Our verdict is Likely benign. Variant got -1 ACMG points: 2P and 3B. PM2 BP4_Moderate BP6

The NM_000059.4(BRCA2):​c.1259A>G​(p.Asp420Gly) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000274 in 1,458,154 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 13/19 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: 0.0000027 (0 hom.)
• Consequence: BRCA2 NM_000059.4 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:5 B:2
• Conservation: PhyloP100: 0.0750

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 -1 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.15607888).
• BP6: Variant 13-32332737-A-G is Benign according to our data. Variant chr13-32332737-A-G is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 184739.We mark this variant Likely_benign, oryginal submissions are: {Likely_benign=2, Uncertain_significance=5}.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
BRCA2	NM_000059.4	c.1259A>G	p.Asp420Gly	missense_variant	10/27	ENST00000380152.8	NP_000050.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
BRCA2	ENST00000380152.8	c.1259A>G	p.Asp420Gly	missense_variant	10/27	5	NM_000059.4	ENSP00000369497	A2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD3 exomes AF: 0.0000122 AC: 3 AN: 246168 Hom.: 0 AF XY: 0.0000150 AC XY: 2 AN XY: 133320

Gnomad AFR exome AF: 0.00

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: 0.0000267

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000274 AC: 4 AN: 1458154 Hom.: 0 Cov.: 35 AF XY: 0.00000414 AC XY: 3 AN XY: 725252

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: 0.0000332

GnomAD4 genome Cov.: 32

Alfa AF: 0.000153 Hom.: 0

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:5 Benign:2

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Hereditary cancer-predisposing syndrome Uncertain:2 Benign:1

Uncertain significance, criteria provided, single submitter	clinical testing	Color Diagnostics, LLC DBA Color Health	Nov 01, 2023	This missense variant replaces aspartic acid with glycine at codon 420 of the BRCA2 protein. Computational prediction suggests that this variant may not impact protein structure and function (internally defined REVEL score threshold <= 0.5, PMID: 27666373). To our knowledge, functional studies have not been performed for this variant. This variant has been reported in individuals and families affected with breast or ovarian cancer (PMID: 20960228, 31851867, 32438681). This variant has been observed together with a pathogenic truncation variant in the same BRCA2 gene in an individual affected with breast cancer (Clinvar variation ID: 184739), and with a pathogenic truncation in the PALB2 gene in an individual affected with breast cancer (Color internal data). This variant has been identified in 3/246168 chromosomes in the general population by the Genome Aggregation Database (gnomAD). Although the available evidence suggests that this variant is unlikely to be disease-causing, additional studies are necessary to determine the role of this variant in disease conclusively. Therefore, this variant is classified as a Variant of Uncertain Significance. -
Uncertain significance, criteria provided, single submitter	clinical testing	Ambry Genetics	Mar 05, 2024	The p.D420G variant (also known as c.1259A>G), located in coding exon 9 of the BRCA2 gene, results from an A to G substitution at nucleotide position 1259. The aspartic acid at codon 420 is replaced by glycine, an amino acid with similar properties. This variant was detected in a non-Ashkenazi Jewish high risk breast/ovarian cancer family from Israel (Laitman Y et al. Breast Cancer Res Treat, 2011 Jun;127:489-95). This variant was also detected in 1/2351 Italian breast and/or ovarian cancer patients (Santonocito C et al. Cancers (Basel), 2020 May;12) and in 1/113 women reported as high risk for hereditary breast cancer (Peker Ey&uuml;bolu et al. OMICS. 2020 Jan;24(1):5-15). 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. Based on the available evidence, 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:2

Uncertain significance, criteria provided, single submitter	clinical testing	Counsyl	Nov 27, 2017	- -
Uncertain significance, criteria provided, single submitter	clinical testing	All of Us Research Program, National Institutes of Health	Nov 20, 2023	This missense variant replaces aspartic acid with glycine at codon 420 of the BRCA2 protein. Computational prediction suggests that this variant may not impact protein structure and function (internally defined REVEL score threshold <= 0.5, PMID: 27666373). To our knowledge, functional studies have not been performed for this variant. This variant has been reported in individuals and families affected with breast or ovarian cancer (PMID: 20960228, 31851867, 32438681). This variant has been observed together with a pathogenic truncation variant in the same BRCA2 gene in an individual affected with breast cancer (Clinvar variation ID: 184739), and with a pathogenic truncation in the PALB2 gene in an individual affected with breast cancer (Color internal data). This variant has been identified in 3/246168 chromosomes in the general population by the Genome Aggregation Database (gnomAD). Although the available evidence suggests that this variant is unlikely to be disease-causing, additional studies are necessary to determine the role of this variant in disease conclusively. Therefore, this variant is classified as a Variant of Uncertain Significance. -

not provided Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Quest Diagnostics Nichols Institute San Juan Capistrano

Aug 20, 2020

- -

Hereditary breast ovarian cancer syndrome Benign:1

Likely benign, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Dec 23, 2023

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.11
BayesDel_addAF	Benign	-0.074	T
BayesDel_noAF	Benign	-0.33
CADD	Benign	16
DANN	Uncertain	1.0
Eigen	Benign	-0.63
Eigen_PC	Benign	-0.61
FATHMM_MKL	Benign	0.047	N
M_CAP	Benign	0.054	D
MetaRNN	Benign	0.16	T;T
MetaSVM	Benign	-0.92	T
MutationTaster	Benign	1.0	N;N
PrimateAI	Benign	0.24	T
PROVEAN	Benign	-1.2	N;N
REVEL	Benign	0.20
Sift	Benign	0.32	T;T
Sift4G	Benign	0.38	T;T
Vest4		0.41
MutPred		0.17		Loss of stability (P = 0.085);Loss of stability (P = 0.085);
MVP		0.84
MPC		0.032
ClinPred		0.099	T
GERP RS		-0.55
gMVP		0.17

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: rs786201654; hg19: chr13-32906874;