13-32363194-T-A

Position:

• chr13-32363194-T-A

Variant summary

Our verdict is Benign. Variant got -11 ACMG points: 0P and 11B. BP4_Moderate BP6_Very_Strong BP7

The NM_000059.4(BRCA2):​c.7992T>A​(p.Ile2664=) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000366 in 1,613,670 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 Likely benign (★★★). Synonymous variant affecting the same amino acid position (i.e. I2664I) has been classified as Likely benign.

• Frequency:
  • Genomes: 𝑓 0.000013 (0 hom., cov: 32)
  • Exomes 𝑓: 0.000039 (0 hom.)
• Consequence: BRCA2 NM_000059.4 synonymous
• Clinical Significance: Likely benign reviewed by expert panel P:1 U:5 B:11
• Conservation: PhyloP100: 0.633

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 Benign. Variant got -11 ACMG points.

• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.34).
• BP6: Variant 13-32363194-T-A is Benign according to our data. Variant chr13-32363194-T-A is described in ClinVar as [Likely_benign]. Clinvar id is 52463.Status of the report is reviewed_by_expert_panel, 3 stars. Variant chr13-32363194-T-A is described in Lovd as [Likely_benign].
• BP7: Synonymous conserved (PhyloP=0.633 with no splicing effect.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
BRCA2	NM_000059.4	c.7992T>A	p.Ile2664=	synonymous_variant	18/27	ENST00000380152.8

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
BRCA2	ENST00000380152.8	c.7992T>A	p.Ile2664=	synonymous_variant	18/27	5	NM_000059.4	A2

Frequencies

GnomAD3 genomes AF: 0.0000131 AC: 2 AN: 152132 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.0000655

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.0000147

Gnomad OTH AF: 0.00

GnomAD3 exomes AF: 0.0000319 AC: 8 AN: 250460 Hom.: 0 AF XY: 0.0000221 AC XY: 3 AN XY: 135464

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.0000707

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.0000390 AC: 57 AN: 1461420 Hom.: 0 Cov.: 31 AF XY: 0.0000413 AC XY: 30 AN XY: 727022

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: 0.0000188

Gnomad4 NFE exome AF: 0.0000486

Gnomad4 OTH exome AF: 0.0000331

GnomAD4 genome AF: 0.0000131 AC: 2 AN: 152250 Hom.: 0 Cov.: 32 AF XY: 0.0000134 AC XY: 1 AN XY: 74452

Gnomad4 AFR AF: 0.00

Gnomad4 AMR AF: 0.0000654

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.0000147

Gnomad4 OTH AF: 0.00

Alfa AF: 0.0000901 Hom.: 0

Bravo AF: 0.0000264

EpiCase AF: 0.0000545

EpiControl AF: 0.0000593

ClinVar

Significance: Likely benign

Submissions summary: Pathogenic:1 Uncertain:5 Benign:11

Revision: reviewed by expert panel

Submissions by phenotype

not provided Uncertain:2 Benign:3

Uncertain significance, criteria provided, single submitter	clinical testing	GeneDx	Nov 09, 2017	This variant is denoted BRCA2 c.7992T>A at the DNA level. Using alternate nomenclature, this variant would be defined as BRCA2 8220T>A. Although the variant is silent at the coding level, preserving an Isoleucine at codon 2664, it has been demonstrated to cause abnormal splicing. However, the splicing error has been characterized as having a partial, or leaky, effect, with some full length transcript also being produced (Th?ry 2011, Houdayer 2012). BRCA2 c.7992T>A has been reported in a patient with bilateral breast cancer and a family history of early onset breast cancer (Th?ry 2011). BRCA2 c.7992T>A was not observed at a significant allele frequency in large population cohorts (Lek 2016). The nucleotide which is altered, a thymine (T) at base 7992, is conserved among mammals. Based on currently available information, it is unclear whether BRCA2 c.7992T>A is pathogenic or benign. We consider it to be a variant of uncertain significance. -
Likely benign, no assertion criteria provided	clinical testing	Clinical Genetics DNA and cytogenetics Diagnostics Lab, Erasmus MC, Erasmus Medical Center	-	- -
Uncertain significance, criteria provided, single submitter	clinical testing	Mayo Clinic Laboratories, Mayo Clinic	Mar 07, 2022	BP6, BP7, PS3_supporting -
Likely benign, criteria provided, single submitter	clinical testing	Quest Diagnostics Nichols Institute San Juan Capistrano	Aug 17, 2021	- -
Likely benign, no assertion criteria provided	clinical testing	Joint Genome Diagnostic Labs from Nijmegen and Maastricht, Radboudumc and MUMC+	-	- -

Breast-ovarian cancer, familial, susceptibility to, 2 Benign:3

Likely benign, reviewed by expert panel	curation	Evidence-based Network for the Interpretation of Germline Mutant Alleles (ENIGMA)	Jun 29, 2017	Synonymous substitution variant, with low bioinformatic likelihood to result in a splicing aberration (Splicing prior probability 0.02; http://priors.hci.utah.edu/PRIORS/). -
Benign, criteria provided, single submitter	clinical testing	Mendelics	May 28, 2019	- -
Likely benign, no assertion criteria provided	clinical testing	BRCAlab, Lund University	Mar 02, 2020	- -

not specified Uncertain:1 Benign:1

Uncertain significance, criteria provided, single submitter	clinical testing	Women's Health and Genetics/Laboratory Corporation of America, LabCorp	Sep 12, 2019	Variant summary: BRCA2 c.7992T>A alters a non-conserved nucleotide resulting in a synonymous change. 5/5 computational tools via ALAMUT predict no significant impact on normal splicing. Another in-silico tool for assessing the pathogenicity of synonymous variants, namely TraP (Transcript-inferred Pathogenicity, Gelfman_2017) predicts that this variant is Benign. However, splicing functional assays demonstrated the variant increases skipping of exon 18 (Thery_2011, Houdayer_2012, Fraile-Bethencourt_2017), however It is complex to interpret the role of variants with partial splicing anomalies in HBOC under the clinical perspective. The variant allele was found at a frequency of 3.2e-05 in 250460 control chromosomes (gnomAD). The available data on variant occurrences in the general population are insufficient to allow any conclusion about variant significance. The variant, c.7992T>A, has been reported in the literature in one individual affected with breast cancer (Thery_BRCA2_EJHG_2011). The data does not allow any conclusion about variant significance. Four clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014 without evidence for independent evaluation (VUS, n=2, likely benign, n=2) and one expert panel (ENIGMA) classified this variant as likely benign. Based on the evidence outlined above, the variant was classified as VUS-possibly benign -
Likely benign, criteria provided, single submitter	clinical testing	Center for Genomic Medicine, Rigshospitalet, Copenhagen University Hospital	Jul 31, 2024	- -

Hereditary cancer-predisposing syndrome Benign:2

Likely benign, criteria provided, single submitter	clinical testing	Color Diagnostics, LLC DBA Color Health	Dec 04, 2015	- -
Likely benign, criteria provided, single submitter	clinical testing	Ambry Genetics	Aug 15, 2018	This alteration is classified as likely benign based on a combination of the following: seen in unaffected individuals, population frequency, intact protein function, lack of segregation with disease, co-occurrence, RNA analysis, in silico models, amino acid conservation, lack of disease association in case-control studies, and/or the mechanism of disease or impacted region is inconsistent with a known cause of pathogenicity. -

Hereditary breast ovarian cancer syndrome;C2675520:Breast-ovarian cancer, familial, susceptibility to, 2 Pathogenic:1

Pathogenic, no assertion criteria provided

research

King Laboratory, University of Washington

Sep 01, 2019

- -

Breast and/or ovarian cancer Uncertain:1

Uncertain significance, no assertion criteria provided

clinical testing

Foulkes Cancer Genetics LDI, Lady Davis Institute for Medical Research

Aug 07, 2015

- -

Malignant tumor of breast Uncertain:1

Uncertain significance, no assertion criteria provided

clinical testing

Department of Pathology and Laboratory Medicine, Sinai Health System

-

The p.Ile2664Ile has been identified in UMD (6X) and the BIC (1X) databases. It is listed in dbSNP database coming from a “clinical source” (ID#: rs80359800) with a “global minor allele frequency of less than 0.001 (1000 genomes). This variant is not expected to have clinical significance because it does not alter an amino acid residue, however it has been suggested to induce incomplete skipping of exon 18 of BRCA2 detected by minigene and in vivo assays (Thery 2011); yet in–silico or computational prediction software (SpliceSiteFinder, MaxEntScan, NNSPLICE, GeneSplicer, HumanSpliceFinder) predicts no change in the splice site prediction score. In summary, the clinical significance of this variant cannot be determined with certainty at this time. Therefore this variant is a variant of unknown significance (VUS). -

BRCA2-related disorder Benign:1

Likely benign, criteria provided, single submitter

clinical testing

PreventionGenetics, part of Exact Sciences

Dec 27, 2020

This variant is classified as likely benign based on ACMG/AMP sequence variant interpretation guidelines (Richards et al. 2015 PMID: 25741868, with internal and published modifications). -

Hereditary breast ovarian cancer syndrome Benign:1

Likely benign, criteria provided, single submitter

clinical testing

Invitae

Jan 30, 2024

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.34
CADD	Benign	6.5
DANN	Benign	0.68

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.020		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: rs80359800; hg19: chr13-32937331;