13-32339102-A-G

Position:

• chr13-32339102-A-G

Variant summary

Our verdict is Likely benign. Variant got -3 ACMG points: 2P and 5B. PM2 BP4_Strong BP6

The NM_000059.4(BRCA2):​c.4747A>G​(p.Ile1583Val) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000031 in 1,613,920 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. I1583T) has been classified as Likely benign.

• Frequency:
  • Genomes: 𝑓 0.0000066 (0 hom., cov: 33)
  • Exomes 𝑓: 0.0000027 (0 hom.)
• Consequence: BRCA2 NM_000059.4 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:2 B:5
• Conservation: PhyloP100: -1.42

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]

BRCA2 (HGNC:):

ACMG classification

Verdict is Likely_benign. Variant got -3 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.04473847).
• BP6: Variant 13-32339102-A-G is Benign according to our data. Variant chr13-32339102-A-G is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 231607.We mark this variant Likely_benign, oryginal submissions are: {Likely_benign=5, Uncertain_significance=2}.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
BRCA2	NM_000059.4	c.4747A>G	p.Ile1583Val	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.4747A>G	p.Ile1583Val	missense_variant	11/27	5	NM_000059.4	ENSP00000369497.3
BRCA2	ENST00000530893.7	c.4378A>G	p.Ile1460Val	missense_variant	11/27	1		ENSP00000499438.2
BRCA2	ENST00000614259.2	n.4747A>G		non_coding_transcript_exon_variant	10/26	2		ENSP00000506251.1

Frequencies

GnomAD3 genomes AF: 0.00000657 AC: 1 AN: 152202 Hom.: 0 Cov.: 33

Gnomad AFR AF: 0.0000241

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.00

Gnomad OTH AF: 0.00

GnomAD4 exome AF: 0.00000274 AC: 4 AN: 1461718 Hom.: 0 Cov.: 45 AF XY: 0.00000413 AC XY: 3 AN XY: 727158

Gnomad4 AFR exome AF: 0.0000896

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: 8.99e-7

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome AF: 0.00000657 AC: 1 AN: 152202 Hom.: 0 Cov.: 33 AF XY: 0.00 AC XY: 0 AN XY: 74356

Gnomad4 AFR AF: 0.0000241

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.00

Gnomad4 OTH AF: 0.00

Bravo AF: 0.00000378

ESP6500AA AF: 0.000227 AC: 1

ESP6500EA AF: 0.00 AC: 0

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:2 Benign:5

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Hereditary cancer-predisposing syndrome Benign:3

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). -
Likely benign, criteria provided, single submitter	clinical testing	Color Diagnostics, LLC DBA Color Health	Oct 29, 2017	- -
Likely benign, criteria provided, single submitter	clinical testing	Ambry Genetics	Apr 17, 2019	This alteration is classified as likely benign based on a combination of the following: seen in unaffected individuals, population frequency, intact protein function, lack of segregation with disease, co-occurrence, RNA analysis, in silico models, amino acid conservation, lack of disease association in case-control studies, and/or the mechanism of disease or impacted region is inconsistent with a known cause of pathogenicity. -

not specified Uncertain:1 Benign:1

Likely benign, criteria provided, single submitter	clinical testing	GeneDx	Jun 10, 2016	This variant is considered likely benign or benign based on one or more of the following criteria: it is a conservative change, it occurs at a poorly conserved position in the protein, it is predicted to be benign by multiple in silico algorithms, and/or has population frequency not consistent with disease. -
Uncertain significance, criteria provided, single submitter	clinical testing	Women's Health and Genetics/Laboratory Corporation of America, LabCorp	Mar 14, 2023	Variant summary: BRCA2 c.4747A>G (p.Ile1583Val) results in a conservative amino acid change in the encoded protein sequence. Five of five in-silico tools predict a benign effect of the variant on protein function. The variant was absent in 250986 control chromosomes. The available data on variant occurrences in the general population are insufficient to allow any conclusion about variant significance. c.4747A>G has been reported in the literature in individuals affected with clinical features of breast and/or ovarian cancer syndrome (Azzollini_2016). These report(s) do not provide unequivocal conclusions about association of the variant with Hereditary Breast And Ovarian Cancer Syndrome. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. Four ClinVar submitters have submitted clinical-significance assessments for this variant to ClinVar after 2014, classifying the variant as uncertain significance (n=1) or likely benign (n=3). Based on the evidence outlined above, the variant was classified as uncertain significance. -

Hereditary breast ovarian cancer syndrome Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Jan 18, 2024

This sequence change replaces isoleucine, which is neutral and non-polar, with valine, which is neutral and non-polar, at codon 1583 of the BRCA2 protein (p.Ile1583Val). This variant is not present in population databases (gnomAD no frequency). This missense change has been observed in individual(s) with clinical features of BRCA2-related conditions (PMID: 27062684). ClinVar contains an entry for this variant (Variation ID: 231607). 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. -

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

Likely benign, criteria provided, single submitter

clinical testing

All of Us Research Program, National Institutes of Health

May 31, 2023

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.063
BayesDel_addAF	Benign	-0.30	T
BayesDel_noAF	Benign	-0.68
CADD	Benign	0.0020
DANN	Benign	0.19
Eigen	Benign	-1.7
Eigen_PC	Benign	-1.7
FATHMM_MKL	Benign	0.013	N
M_CAP	Benign	0.025	D
MetaRNN	Benign	0.045	T;T
MetaSVM	Benign	-0.95	T
PrimateAI	Benign	0.21	T
PROVEAN	Benign	0.28	N;N
REVEL	Benign	0.024
Sift	Benign	1.0	T;T
Sift4G	Benign	1.0	T;T
Vest4		0.092
MVP		0.45
MPC		0.019
ClinPred		0.030	T
GERP RS		-3.4
gMVP		0.060

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: rs56072130; hg19: chr13-32913239;