chr13-32362591-G-T

Position:

• chr13-32362591-G-T

Variant summary

Our verdict is Likely pathogenic. Variant got 6 ACMG points: 6P and 0B. PM1 PM2 PP3_Moderate

The NM_000059.4(BRCA2):​c.7874G>T​(p.Arg2625Ile) variant causes a missense change. The variant allele was found at a frequency of 0.000000684 in 1,461,802 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic 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. R2625K) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: BRCA2 NM_000059.4 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:1 U:4
• Conservation: PhyloP100: 5.81

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_pathogenic. Variant got 6 ACMG points.

• PM1: In a hotspot region, there are 7 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 4 benign, 16 uncertain in NM_000059.4
• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.883

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
BRCA2	NM_000059.4	c.7874G>T	p.Arg2625Ile	missense_variant	17/27	ENST00000380152.8

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
BRCA2	ENST00000380152.8	c.7874G>T	p.Arg2625Ile	missense_variant	17/27	5	NM_000059.4	A2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461802 Hom.: 0 Cov.: 33 AF XY: 0.00 AC XY: 0 AN XY: 727204

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: 8.99e-7

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:1 Uncertain:4

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Hereditary cancer-predisposing syndrome Pathogenic:1 Uncertain:1

Uncertain significance, criteria provided, single submitter	clinical testing	Color Diagnostics, LLC DBA Color Health	Feb 02, 2023	This missense variant replaces arginine with isoleucine at codon 2625 of the BRCA2 protein. Computational prediction suggests that this variant may have deleterious impact on protein structure and function (internally defined REVEL score threshold >= 0.7, PMID: 27666373). Functional studies have shown that this variant impairs homology-directed DNA repair (PMID: 33609447). This variant has been reported in an individual affected with prostate cancer (PMID: 31874108). In a large breast cancer case-control study conducted by the BRIDGES consortium, this variant was reported in 2/60466 cases and 1/53461 unaffected controls (PMID: 33471991; Leiden Open Variation Database DB-ID BRCA2_008629). 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. -
Likely pathogenic, criteria provided, single submitter	clinical testing	Ambry Genetics	Jan 05, 2022	The p.R2625I variant (also known as c.7874G>T), located in coding exon 16 of the BRCA2 gene, results from a G to T substitution at nucleotide position 7874. The arginine at codon 2625 is replaced by isoleucine, an amino acid with similar properties. This variant was non-functional in a homology-directed DNA repair (HDR) assay (Ambry internal data). In addition, this variant was reported in 2/60,466 breast cancer cases and in 1/53,461 controls (Dorling et al. N Engl J Med. 2021 02;384:428-439). This alteration is also predicted to destabilize the local structure and disrupt the protein binding ability of BRCA2 (Yang H et al. Science 2002 Sep;297:1837-48; Marston NJ et al. Mol. Cell. Biol. 1999 Jul;19:4633-42; Ambry internal data). This amino acid position is well conserved in available vertebrate species. In addition, this alteration is predicted to be deleterious by in silico analysis. Based on the majority of available evidence to date, this variant is likely to be pathogenic. -

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

Uncertain significance, criteria provided, single submitter

clinical testing

All of Us Research Program, National Institutes of Health

Jun 28, 2023

This missense variant replaces arginine with isoleucine at codon 2625 of the BRCA2 protein. Computational prediction suggests that this variant may have deleterious impact on protein structure and function (internally defined REVEL score threshold >= 0.7, PMID: 27666373). Functional studies have shown that this variant impairs homology-directed DNA repair (PMID: 33609447). In a large breast cancer case-control study conducted by the BRIDGES consortium, this variant was reported in 2/60466 cases and 1/53461 unaffected controls (p-value=1; Leiden Open Variation Database DB-ID BRCA2_008629) (PMID: 33471991). 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. -

not provided Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

GeneDx

Jun 10, 2015

This variant is denoted BRCA2 c.7874G>T at the cDNA level, p.Arg2625Ile (R2625I) at the protein level, and results in the change of an Arginine to an Isoleucine (AGA>ATA). Using alternate nomenclature, this variant would be defined as BRCA2 8102G>T. This variant has not, to our knowledge, been published in the literature as pathogenic or benign. BRCA2 Arg2625Ile 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 Arginine and Isoleucine differ in polarity, charge, size or other properties, this is considered a non-conservative amino acid substitution. BRCA2 Arg2625Ile occurs at a position where amino acids with properties similar to Arginine are tolerated across species and is located in the DNA-binding domain (Borg 2010). In silico analyses predict that this variant is probably damaging to protein structure and function. Based on currently available information, it is unclear whether BRCA2 Arg2625Ile is pathogenic or benign. We consider it to be a variant of uncertain significance. -

Hereditary breast ovarian cancer syndrome Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Sep 03, 2021

This sequence change replaces arginine with isoleucine at codon 2625 of the BRCA2 protein (p.Arg2625Ile). The arginine residue is highly conserved and there is a moderate physicochemical difference between arginine and isoleucine. 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. Algorithms developed to predict the effect of missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be disruptive. ClinVar contains an entry for this variant (Variation ID: 419217). This variant has not been reported in the literature in individuals affected with BRCA2-related conditions. This variant is not present in population databases (ExAC no frequency). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.84
BayesDel_addAF	Pathogenic	0.30	D
BayesDel_noAF	Pathogenic	0.20
CADD	Uncertain	25
DANN	Uncertain	0.98
Eigen	Pathogenic	0.78
Eigen_PC	Pathogenic	0.71
FATHMM_MKL	Uncertain	0.94	D
M_CAP	Pathogenic	0.33	D
MetaRNN	Pathogenic	0.88	D;D
MetaSVM	Uncertain	0.74	D
MutationTaster	Benign	1.0	D;D
PrimateAI	Uncertain	0.62	T
PROVEAN	Benign	-2.1	N;N
REVEL	Pathogenic	0.80
Sift	Pathogenic	0.0	D;D
Sift4G	Uncertain	0.0020	D;D
Vest4		0.68
MutPred		0.70		Loss of MoRF binding (P = 0.0231);Loss of MoRF binding (P = 0.0231);
MVP		0.96
MPC		0.19
ClinPred		0.96	D
GERP RS		4.8
gMVP		0.72

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: rs864622552; hg19: chr13-32936728; COSMIC: COSV104701323;