chr13-32396935-T-G

Position:

• chr13-32396935-T-G

Variant summary

Our verdict is Uncertain significance. Variant got 4 ACMG points: 4P and 0B. PM2 PP3_Moderate

The NM_000059.4(BRCA2):​c.9539T>G​(p.Leu3180Arg) variant causes a missense change involving the alteration of a non-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 Uncertain significance (★★).

• Frequency: Genomes: not found (cov: 33)
• Consequence: BRCA2 NM_000059.4 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 3.04

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 Uncertain_significance. Variant got 4 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.922

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
BRCA2	NM_000059.4	c.9539T>G	p.Leu3180Arg	missense_variant	26/27	ENST00000380152.8	NP_000050.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
BRCA2	ENST00000380152.8	c.9539T>G	p.Leu3180Arg	missense_variant	26/27	5	NM_000059.4	ENSP00000369497.3
BRCA2	ENST00000530893.7	c.9170T>G	p.Leu3057Arg	missense_variant	26/27	1		ENSP00000499438.2
BRCA2	ENST00000614259.2	n.*1597T>G		non_coding_transcript_exon_variant	25/26	2		ENSP00000506251.1
BRCA2	ENST00000614259.2	n.*1597T>G		3_prime_UTR_variant	25/26	2		ENSP00000506251.1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 33

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Hereditary cancer-predisposing syndrome Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Color Diagnostics, LLC DBA Color Health

Oct 02, 2019

This missense variant replaces leucine with arginine at codon 3180 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). Splice site prediction tools suggest that this variant may not impact RNA splicing. To our knowledge, functional studies have not been performed for this variant. This variant has been reported in 1 individual affected with ovarian cancer (PMID: 14507240). 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. -

Hereditary breast ovarian cancer syndrome Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Jul 02, 2022

Advanced modeling of experimental studies (such as gene expression, population dynamics, functional pathways, and cell-cycle effects in cell culture) performed at Invitae indicates that this missense variant is not expected to disrupt 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. Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may create or strengthen a splice site. ClinVar contains an entry for this variant (Variation ID: 571797). This missense change has been observed in individual(s) with ovarian cancer (PMID: 14507240). This variant is not present in population databases (gnomAD no frequency). This sequence change replaces leucine, which is neutral and non-polar, with arginine, which is basic and polar, at codon 3180 of the BRCA2 protein (p.Leu3180Arg). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.57
BayesDel_addAF	Pathogenic	0.40	D
BayesDel_noAF	Pathogenic	0.33
CADD	Uncertain	24
DANN	Uncertain	1.0
Eigen	Uncertain	0.67
Eigen_PC	Uncertain	0.63
FATHMM_MKL	Uncertain	0.96	D
M_CAP	Uncertain	0.23	D
MetaRNN	Pathogenic	0.92	D;D
MetaSVM	Uncertain	0.63	D
PrimateAI	Uncertain	0.53	T
PROVEAN	Benign	-1.7	N;N
REVEL	Pathogenic	0.71
Sift	Pathogenic	0.0	D;D
Sift4G	Pathogenic	0.0	D;D
Vest4		0.88
MutPred		0.72		Loss of helix (P = 0.0104);Loss of helix (P = 0.0104);
MVP		0.97
MPC		0.18
ClinPred		0.98	D
GERP RS		5.9
gMVP		0.84

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: rs397507431; hg19: chr13-32971072; COSMIC: COSV66337295; COSMIC: COSV66337295;