rs41293509

Positions:

• chr13-32357919-G-A
• chr13-32357919-G-C
• chr13-32357919-G-T

Variant summary

Our verdict is Uncertain significance. Variant got 5 ACMG points: 5P and 0B. PM2 PP3_Moderate PP5

The NM_000059.4(BRCA2):​c.7795G>A​(p.Glu2599Lys) variant causes a missense change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

• Frequency: Genomes: not found (cov: 32)
• Consequence: BRCA2 NM_000059.4 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:1 U:2
• Conservation: PhyloP100: 9.31

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 5 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.885
• PP5: Variant 13-32357919-G-A is Pathogenic according to our data. Variant chr13-32357919-G-A is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 231552.We mark this variant Likely_pathogenic, oryginal submissions are: {Uncertain_significance=2, Likely_pathogenic=1}.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
BRCA2	NM_000059.4	c.7795G>A	p.Glu2599Lys	missense_variant	16/27	ENST00000380152.8	NP_000050.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
BRCA2	ENST00000380152.8	c.7795G>A	p.Glu2599Lys	missense_variant	16/27	5	NM_000059.4	ENSP00000369497.3
BRCA2	ENST00000530893.7	c.7426G>A	p.Glu2476Lys	missense_variant	16/27	1		ENSP00000499438.2
BRCA2	ENST00000614259.2	n.7795G>A		non_coding_transcript_exon_variant	15/26	2		ENSP00000506251.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 32

Alfa AF: 0.0000487 Hom.: 3239

Bravo AF: 0.00000378

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:1 Uncertain:2

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Hereditary cancer-predisposing syndrome Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

Ambry Genetics

Dec 12, 2023

The p.E2599K variant (also known as c.7795G>A), located in coding exon 15 of the BRCA2 gene, results from a G to A substitution at nucleotide position 7795. The glutamic acid at codon 2599 is replaced by lysine, an amino acid with similar properties. This alteration has been reported in the literature in individuals diagnosed with prostate cancer (Kote-Jarai et al. Br J Cancer. 2011 Oct 11;105(8):1230-4) and triple negative breast cancer (Muendlein A et al J Cancer Res Clin Oncol. 2015 Nov;141(11):2005-12). In addition, the variant was detected in conjunction with another pathogenic mutation in the BRCA2 gene in an individual affected with Fanconi Anemia, although phase was not reported (Knies K et al. PLoS One. 2012;7(12):e52648). Furthermore, this alteration was non-functional in a homology directed DNA repair assay (Ambry internal data). This amino acid position is highly conserved in available vertebrate species. In addition, this alteration is predicted to be deleterious by in silico analysis. 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. However, because this variant is identified in one or more patients with Fanconi anemia it may be hypomorphic and thus, carriers of this variant and their families may present with reduced risks, and not with the typical clinical characteristics of a high-risk pathogenic BRCA2 alteration. As risk estimates are unknown at this time, clinical correlation is advised. -

not provided Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

GeneDx

Apr 08, 2022

Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports that this missense variant does not alter protein structure/function; Observed with a second BRCA2 variant, phase (cis or trans) not confirmed, in an individual with Fanconi anemia in published literature (Knies 2012); Observed in individuals with a personal history of prostate cancer or breast cancer in published literature (Kote-Jarai 2011, Muendlein 2015); Also known as 8023G>A; This variant is associated with the following publications: (PMID: 21952622, 25971625, 12228710, 23285130) -

Hereditary breast ovarian cancer syndrome Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Oct 17, 2023

This sequence change replaces glutamic acid, which is acidic and polar, with lysine, which is basic and polar, at codon 2599 of the BRCA2 protein (p.Glu2599Lys). This variant is not present in population databases (gnomAD no frequency). This missense change has been observed in individual(s) with prostate cancer or breast cancer and Fanconi anemia (PMID: 21952622, 23285130, 25971625). ClinVar contains an entry for this variant (Variation ID: 231552). 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) has been performed at Invitae for this missense variant, however the output from this modeling did not meet the statistical confidence thresholds required to predict the impact of this variant on BRCA2 protein function. 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	Pathogenic	0.88
BayesDel_addAF	Pathogenic	0.34	D
BayesDel_noAF	Pathogenic	0.25
CADD	Pathogenic	29
DANN	Uncertain	1.0
Eigen	Pathogenic	0.94
Eigen_PC	Pathogenic	0.88
FATHMM_MKL	Pathogenic	0.99	D
M_CAP	Pathogenic	0.45	D
MetaRNN	Pathogenic	0.89	D;D
MetaSVM	Pathogenic	0.96	D
PrimateAI	Uncertain	0.76	T
PROVEAN	Benign	-1.2	N;N
REVEL	Pathogenic	0.80
Sift	Pathogenic	0.0	D;D
Sift4G	Pathogenic	0.0	D;D
Vest4		0.85
MutPred		0.70		Gain of methylation at E2599 (P = 0.0202);Gain of methylation at E2599 (P = 0.0202);
MVP		0.98
MPC		0.17
ClinPred		1.0	D
GERP RS		5.2
gMVP		0.84

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.040		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: rs41293509; hg19: chr13-32932056;