chr13-32362543-G-A

Position:

• chr13-32362543-G-A

Variant summary

Our verdict is Pathogenic. Variant got 12 ACMG points: 12P and 0B. PM2 PP3_Moderate PP5_Very_Strong

The NM_000059.4(BRCA2):​c.7826G>A​(p.Gly2609Asp) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,650 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 Likely pathogenic (★★).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: BRCA2 NM_000059.4 missense
• Clinical Significance: Likely pathogenic criteria provided, multiple submitters, no conflicts P:5 U:2
• Conservation: PhyloP100: 9.85

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 Pathogenic. Variant got 12 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.928
• PP5: Variant 13-32362543-G-A is Pathogenic according to our data. Variant chr13-32362543-G-A is described in ClinVar as [Likely_pathogenic]. Clinvar id is 52423.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
BRCA2	NM_000059.4	c.7826G>A	p.Gly2609Asp	missense_variant	17/27	ENST00000380152.8	NP_000050.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
BRCA2	ENST00000380152.8	c.7826G>A	p.Gly2609Asp	missense_variant	17/27	5	NM_000059.4	ENSP00000369497	A2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461650 Hom.: 0 Cov.: 33 AF XY: 0.00000138 AC XY: 1 AN XY: 727134

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: Likely pathogenic

Submissions summary: Pathogenic:5 Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Hereditary cancer-predisposing syndrome Pathogenic:2

Likely pathogenic, criteria provided, single submitter	clinical testing	Ambry Genetics	May 23, 2024	The p.G2609D variant (also known as c.7826G>A), located in coding exon 16 of the BRCA2 gene, results from a G to A substitution at nucleotide position 7826. The glycine at codon 2609 is replaced by aspartic acid, an amino acid with similar properties. This alteration has demonstrated defective homology-directed repair in several functional studies (Guidugli L et al. Hum. Mutat. 2014 Feb;35:151-64; Guidugli L et al. Am. J. Hum. Genet. 2018 02;102(2):233-248, Caleca L. et al. Cancers (Basel). 2019 Jan;11(2), Mesman RLS. et al. Genet Med. 2019 02;21(2):293-302). In addition, this alteration was reported as pathogenic based on sensitivity to PARP inhibitors in a high-throughput in vitro assay performed in a a human colorectal adenoma cell line (Ikegami M. et al. Nat Commun. 2020 05;11(1):2573). Based on internal structural analysis, this alteration is likely to disrupt DSS1 binding and is predicted to be as destabilizing to the local structure as other known pathogenic variants (Yang H et al. Science 2002 Sep;297:1837-48; Ambry internal data). This amino acid position is highly conserved in available vertebrate species. In addition, several in silico tools predict a deleterious impact for this alteration. This variant is considered to be rare based on population cohorts in the Genome Aggregation Database (gnomAD). Based on the majority of available evidence to date, this variant is likely to be pathogenic. -
Likely pathogenic, criteria provided, single submitter	clinical testing	Color Diagnostics, LLC DBA Color Health	Jun 08, 2020	This missense variant replaces glycine with aspartic acid at codon 2609 the DNA binding domain 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-mediated DNA repair activity of BRCA2 protein (PMID: 23108138, 29988080, 30696104) and was unable to complement BRCA2-deficiency in a cell viability-based assay (PMID: 32444794). A multifactorial analysis has determined this variant to be likely pathogenic based on clinical history of carrier individuals and functional studies (PMID: 23108138). This variant has not been identified in the general population by the Genome Aggregation Database (gnomAD). Based on the available evidence, this variant is classified as Likely Pathogenic. -

Hereditary breast ovarian cancer syndrome Pathogenic:2

Likely pathogenic, criteria provided, single submitter	curation	Cancer Variant Interpretation Group UK, Institute of Cancer Research, London	Oct 10, 2018	Data used in classification: The frequency of this variant is 0/138,632 individuals (gnomAD) (PM2_mod). This variant is predicted deleterious on AlignGVGD (class: C65), SIFT (Deleterious), Polyphen2 HumVar (probably damaging) and CADD (33) (PP3_sup). The variant is in the DNA-binding domain of BRCA2 (PM1_sup). In the BRCA2 Homology-Directed Repair Activity assay for the DNA Binding Domain (Guidugli et al Cancer Res 2013;73:265-275,Couch Lab) the variant has a probability of pathogenicity of 1.0 (PS3_strong). Data not used in classification: There are additional reports of this variant in ClinVar (2), UMD (1), BIC (1), and BRCA2 LOVD (2). -
Likely pathogenic, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	May 10, 2023	ClinVar contains an entry for this variant (Variation ID: 52423). In summary, the currently available evidence indicates that the variant is pathogenic, but additional data are needed to prove that conclusively. Therefore, this variant has been classified as Likely Pathogenic. Experimental studies have shown that this missense change affects BRCA2 function (PMID: 21990134, 23108138, 29394989, 29884841, 29988080). Based on a multifactorial likelihood algorithm using genetic, in silico, and/or statistical data, this variant has been determined to have a high probability of being pathogenic (PMID: 21990134). This missense change has been observed in individual(s) with clinical features of BRCA2-related conditions (PMID: 10923033). This variant is not present in population databases (gnomAD no frequency). This sequence change replaces glycine, which is neutral and non-polar, with aspartic acid, which is acidic and polar, at codon 2609 of the BRCA2 protein (p.Gly2609Asp). -

not provided Pathogenic:1 Uncertain:1

Uncertain significance, no assertion criteria provided	clinical testing	Department of Pathology and Laboratory Medicine, Sinai Health System	-	The BRCA2 p.Gly2609Asp variant was identified in the literature however the frequency of this variant in an affected population was not provided. The variant was also identified in the following databases: dbSNP (ID: rs80359009) as "With Likely pathogenic, Uncertain significance allele", ClinVar (1x likely pathogenic, 1x uncertain significance), Clinvitae, LOVD 3.0 (2x, predicted deleterious), UMD-LSDB (1x, unknown/unclassified variant), and the BIC Database (1x, unknown clinical significance). The variant was not identified in Cosmic, MutDB, ARUP Laboratories, or the Zhejiang Colon Cancer Database. The variant was not identified in the control databases: the 1000 Genomes Project, the NHLBI GO Exome Sequencing Project, the Exome Aggregation Consortium (August 8th 2016), or the Genome Aggregation Database (Feb 27, 2017). One research group has published a functional assay measuring homology-directed repair activity and determined that that variant protein had reduced activity, with a prediction of it being deleterious (Guidugli 2013, Guidugli 2013). Two multifactorial-likelihood models and one protein-likelihood ratio model predict the variant to be likely deleterious (Guidugli 2013, Karchin 2008, Lindor 2012). In addition, an in silico study predicted that the variant would result in the loss of a potential exonic splicing enhancer (Pettigrew 2008). The p.Gly2609 residue is conserved across mammals and other organisms, and computational analyses (PolyPhen-2, SIFT, AlignGVGD, BLOSUM, MutationTaster) suggest that the variant may impact the protein; however, this information is not predictive enough to assume pathogenicity. The variant occurs outside of the splicing consensus sequence and 4 of 5 in silico or computational prediction software programs (SpliceSiteFinder, MaxEntScan, NNSPLICE, GeneSplicer, HumanSpliceFinder) predict a greater than 10% difference in splicing. However, this information is not predictive enough to assume pathogenicity. In summary, based on the above information the clinical significance of this variant cannot be determined with certainty at this time. This variant is classified as a variant of uncertain significance. -
Likely pathogenic, criteria provided, single submitter	clinical testing	CeGaT Center for Human Genetics Tuebingen	Jan 01, 2023	- -

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

Uncertain significance, no assertion criteria provided

clinical testing

Breast Cancer Information Core (BIC) (BRCA2)

Oct 29, 2001

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.86
BayesDel_addAF	Pathogenic	0.43	D
BayesDel_noAF	Pathogenic	0.38
CADD	Pathogenic	27
DANN	Uncertain	1.0
Eigen	Pathogenic	0.98
Eigen_PC	Pathogenic	0.96
FATHMM_MKL	Pathogenic	1.0	D
M_CAP	Pathogenic	0.65	D
MetaRNN	Pathogenic	0.93	D;D
MetaSVM	Pathogenic	0.97	D
MutationTaster	Benign	1.0	D;D
PrimateAI	Uncertain	0.78	T
PROVEAN	Benign	-1.9	N;N
REVEL	Pathogenic	0.93
Sift	Pathogenic	0.0	D;D
Sift4G	Pathogenic	0.0	D;D
Vest4		0.70
MutPred		0.79		Loss of catalytic residue at V2610 (P = 0.0553);Loss of catalytic residue at V2610 (P = 0.0553);
MVP		0.98
MPC		0.18
ClinPred		0.99	D
GERP RS		5.7
gMVP		0.74

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: rs80359009; hg19: chr13-32936680;