rs397507354

Positions:

• chr13-32339930-A-G

Variant summary

Our verdict is Uncertain significance. Variant got 0 ACMG points: 2P and 2B. PM2 BP4_Moderate

The NM_000059.4(BRCA2):​c.5575A>G​(p.Ile1859Val) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000688 in 1,454,414 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 15/19 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. I1859M) has been classified as Likely benign.

• 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:10 B:1
• Conservation: PhyloP100: 0.0170

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 0 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.0790883).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
BRCA2	NM_000059.4	c.5575A>G	p.Ile1859Val	missense_variant	11/27	ENST00000380152.8

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
BRCA2	ENST00000380152.8	c.5575A>G	p.Ile1859Val	missense_variant	11/27	5	NM_000059.4	A2

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 6.88e-7 AC: 1 AN: 1454414 Hom.: 0 Cov.: 46 AF XY: 0.00 AC XY: 0 AN XY: 722800

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: 9.02e-7

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 33

EpiCase AF: 0.0000545

EpiControl AF: 0.00

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:10 Benign:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Breast-ovarian cancer, familial, susceptibility to, 2 Uncertain:4

Uncertain significance, no assertion criteria provided	clinical testing	Sharing Clinical Reports Project (SCRP)	Sep 22, 2010	- -
Uncertain significance, criteria provided, single submitter	clinical testing	Division of Medical Genetics, University of Washington	Jan 22, 2020	To our knowledge, this sequence variant has not been previously reported in the literature. This variant is not present in population databases (https://gnomad.broadinstitute.org/). In silico analyses indicate that this variant does not alter protein structure/function. Thus, it is unknown at this time whether this variant increases cancer risk. PM2; BP4 -
Uncertain significance, criteria provided, single submitter	clinical testing	All of Us Research Program, National Institutes of Health	Sep 17, 2023	This missense variant replaces isoleucine with valine at codon 1859 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 reported for this variant. This variant has not been reported in individuals affected with BRCA2-related disorders in the literature, but has been observed in an unaffected individual (PMID: 33471991; Leiden Open Variation Database DB-ID BRCA2_008352). This variant has not been identified in the general population by the Genome Aggregation Database (gnomAD). The available evidence is insufficient 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	St. Jude Molecular Pathology, St. Jude Children's Research Hospital	Jun 08, 2022	The BRCA2 c.5575A>G (p.Ile1859Val) missense change is absent in gnomAD v2.1.1 (https://gnomad.broadinstitute.org/). This variant was detected in 2 of 138,342 individuals who underwent multi-gene panel testing including BRCA1 and BRCA2 and did not have a pathogenic or likely pathogenic variant in another gene related to hereditary breast cancer (PMID: 31853058), as well as in one woman older than 70 years of age who has never had cancer (FLOSSIES, https://whi.color.com/). The in silico tool REVEL predicts a benign effect on protein function, but to our knowledge this prediction has not been confirmed by functional studies. In summary, the evidence currently available is insufficient to determine the role of this variant in hereditary breast and ovarian cancer syndrome and/or Fanconi anemia. It has therefore been classified as of uncertain significance. -

not provided Uncertain:3

Uncertain significance, criteria provided, single submitter	clinical testing	Quest Diagnostics Nichols Institute San Juan Capistrano	Sep 14, 2023	In the published literature, this variant has been reported to be located in a region of the BRCA2 gene that is tolerant to missense changed (PMID: 31911673 (2020)). In a large-scale breast cancer association study, the variant was observed in an unaffected individual (PMID: 33471991 (2021)). This variant has not been reported in large, multi-ethnic general populations (Genome Aggregation Database, http://gnomad.broadinstitute.org). Analysis of this variant using bioinformatics tools for the prediction of the effect of amino acid changes on protein structure and function yielded predictions that this variant is benign. Based on the available information, we are unable to determine the clinical significance of this variant. -
Uncertain significance, criteria provided, single submitter	clinical testing	Women's Health and Genetics/Laboratory Corporation of America, LabCorp	Mar 13, 2017	Variant summary: The BRCA2 c.5575A>G (p.Ile1859Val) variant causes a missense change involving the alteration of a non-conserved nucleotide. 4/5 in silico tools predict a benign outcome for this variant. This variant is absent in 120450 control chromosomes. In addition, multiple clinical diagnostic laboratories/reputable databases classified this variant as uncertain significance. The variant of interest has not, to our knowledge, been reported in affected individuals via publications; nor evaluated for functional impact by in vivo/vitro studies. The variant is located in one of the BRCA repeats that is critical for binding to RAD51 (a key protein in DNA recombinational repair) and resistance to methyl methanesulphonate treatment (IPR002093). However, because of the absence of clinical information and the lack of functional studies, the variant is classified as a variant of uncertain significance (VUS) until additional information becomes available. -
Uncertain significance, criteria provided, single submitter	clinical testing	GeneDx	Jul 30, 2015	This variant is denoted BRCA2 c.5575A>G at the cDNA level, p.Ile1859Val (I1859V) at the protein level, and results in the change of an Isoleucine to a Valine (ATT>GTT). Using alternate nomenclature, this variant would be defined as BRCA2 5803A>G. This variant has not, to our knowledge, been published in the literature as pathogenic or benign. BRCA2 Ile1859Val 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 Isoleucine and Valine share similar properties, this is considered a conservative amino acid substitution. BRCA2 Ile1859Val occurs at a position that is not conserved and is located in the 6th BRC repeat domain and RAD51 binding region (Roy 2012, UniProt). In silico analyses predict that this variant is unlikely to alter protein structure or function. Based on currently available information, it is unclear whether BRCA2 Ile1859Val is pathogenic or benign. We consider it to be a variant of uncertain significance. -

Hereditary cancer-predisposing syndrome Uncertain:2 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	Color Diagnostics, LLC DBA Color Health	Dec 21, 2022	This missense variant replaces isoleucine with valine at codon 1859 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 reported for this variant. This variant has not been reported in individuals affected with BRCA2-related disorders in the literature, but has been observed in an unaffected individual (PMID: 33471991; Leiden Open Variation Database DB-ID BRCA2_008352). This variant has not been identified in the general population by the Genome Aggregation Database (gnomAD). The available evidence is insufficient 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	Feb 21, 2023	The p.I1859V variant (also known as c.5575A>G), located in coding exon 10 of the BRCA2 gene, results from an A to G substitution at nucleotide position 5575. The isoleucine at codon 1859 is replaced by valine, an amino acid with highly similar properties. This amino acid position is poorly 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. -

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 1859 of the BRCA2 protein (p.Ile1859Val). This variant is not present in population databases (gnomAD no frequency). This variant has not been reported in the literature in individuals affected with BRCA2-related conditions. ClinVar contains an entry for this variant (Variation ID: 37974). 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	0.072
BayesDel_addAF	Benign	-0.046	T
BayesDel_noAF	Benign	-0.30
CADD	Benign	3.1
DANN	Benign	0.13
Eigen	Benign	-1.1
Eigen_PC	Benign	-1.1
FATHMM_MKL	Benign	0.039	N
M_CAP	Benign	0.020	T
MetaRNN	Benign	0.079	T;T
MetaSVM	Benign	-0.99	T
MutationTaster	Benign	1.0	N;N
PrimateAI	Benign	0.27	T
PROVEAN	Benign	-0.21	N;N
REVEL	Benign	0.22
Sift	Benign	1.0	T;T
Sift4G	Benign	1.0	T;T
Vest4		0.25
MutPred		0.58		Gain of methylation at K1860 (P = 0.0813);Gain of methylation at K1860 (P = 0.0813);
MVP		0.61
MPC		0.020
ClinPred		0.079	T
GERP RS		1.3
gMVP		0.058

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: rs397507354; hg19: chr13-32914067;