13-32344602-A-T

Variant names:

• chr13-32344602-A-T
• rs576279166
• NM_000059.4:c.6886A>T

Variant summary

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

The NM_000059.4(BRCA2):​c.6886A>T​(p.Ile2296Leu) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000699 in 1,430,900 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★). Another nucleotide change resulting in the same amino acid substitution has been previously reported as Likely benign in Lovd.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 7.0e-7 (0 hom.)
• Consequence: BRCA2 NM_000059.4 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:3
• Conservation: PhyloP100: 2.29

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 2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
BRCA2	NM_000059.4	c.6886A>T	p.Ile2296Leu	missense_variant	Exon 12 of 27	ENST00000380152.8	NP_000050.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
BRCA2	ENST00000380152.8	c.6886A>T	p.Ile2296Leu	missense_variant	Exon 12 of 27	5	NM_000059.4	ENSP00000369497.3
BRCA2	ENST00000530893.7	c.6517A>T	p.Ile2173Leu	missense_variant	Exon 12 of 27	1		ENSP00000499438.2
BRCA2	ENST00000614259.2	n.6886A>T		non_coding_transcript_exon_variant	Exon 11 of 26	2		ENSP00000506251.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.99e-7 AC: 1 AN: 1430900 Hom.: 0 Cov.: 29 AF XY: 0.00 AC XY: 0 AN XY: 713524

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: 0.00

Gnomad4 OTH exome AF: 0.0000168

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:3

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

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

May 04, 2023

All of Us Research Program, National Institutes of Health

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This missense variant replaces isoleucine with leucine at codon 2296 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 been reported in an individual affected with breast cancer (PMID: 33471991; Leiden Open Variation Database DB-ID BRCA2_008529). 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 cancer-predisposing syndrome Uncertain:1

Apr 05, 2023

Color Diagnostics, LLC DBA Color Health

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This missense variant replaces isoleucine with leucine at codon 2296 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 been reported in an individual affected with breast cancer (PMID: 33471991; Leiden Open Variation Database DB-ID BRCA2_008529). 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

May 13, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces isoleucine, which is neutral and non-polar, with leucine, which is neutral and non-polar, at codon 2296 of the BRCA2 protein (p.Ile2296Leu). This variant is not present in population databases (gnomAD no frequency). This missense change has been observed in individual(s) with breast and/or ovarian cancer (PMID: 30555256). ClinVar contains an entry for this variant (Variation ID: 924286). 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%. Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. 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	0.12
BayesDel_addAF	Uncertain	0.085	D
BayesDel_noAF	Benign	-0.12
CADD	Benign	17
DANN	Uncertain	0.98
Eigen	Benign	-0.21
Eigen_PC	Benign	-0.15
FATHMM_MKL	Uncertain	0.78	D
M_CAP	Benign	0.034	D
MetaRNN	Benign	0.24	T;T
MetaSVM	Benign	-0.60	T
PrimateAI	Benign	0.46	T
PROVEAN	Benign	-0.46	N;N
REVEL	Uncertain	0.48
Sift	Uncertain	0.026	D;D
Sift4G	Benign	0.18	T;T
Vest4		0.43
MutPred		0.21		Gain of disorder (P = 0.1764);Gain of disorder (P = 0.1764);
MVP		0.81
MPC		0.065
ClinPred		0.62	D
GERP RS		1.1
gMVP		0.14

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.24		Details are displayed if max score is > 0.2
DS_AL_spliceai		0.24		Position offset: -44

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

LitVar

Other links and lift over

dbSNP: rs576279166; hg19: chr13-32918739;