chr13-32333333-C-T

Position:

• chr13-32333333-C-T

Variant summary

Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PVS1 PM2 PP5_Very_Strong

The NM_000059.4(BRCA2):​c.1855C>T​(p.Gln619*) variant causes a stop gained change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000687 in 1,456,638 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 Pathogenic (★★★). Variant results in nonsense mediated mRNA decay.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.9e-7 (0 hom.)
• Consequence: BRCA2 NM_000059.4 stop_gained
• Clinical Significance: Pathogenic reviewed by expert panel P:12
• Conservation: PhyloP100: 0.805

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 Pathogenic. Variant got 18 ACMG points.

• PVS1: Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 13-32333333-C-T is Pathogenic according to our data. Variant chr13-32333333-C-T is described in ClinVar as [Pathogenic]. Clinvar id is 51216.Status of the report is reviewed_by_expert_panel, 3 stars. Variant chr13-32333333-C-T is described in Lovd as [Pathogenic]. Variant chr13-32333333-C-T is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
BRCA2	NM_000059.4	c.1855C>T	p.Gln619*	stop_gained	10/27	ENST00000380152.8	NP_000050.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
BRCA2	ENST00000380152.8	c.1855C>T	p.Gln619*	stop_gained	10/27	5	NM_000059.4	ENSP00000369497.3
BRCA2	ENST00000530893.7	c.1486C>T	p.Gln496*	stop_gained	10/27	1		ENSP00000499438.2
BRCA2	ENST00000614259.2	n.1855C>T		non_coding_transcript_exon_variant	9/26	2		ENSP00000506251.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.87e-7 AC: 1 AN: 1456638 Hom.: 0 Cov.: 35 AF XY: 0.00000138 AC XY: 1 AN XY: 724246

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: 0.0000118

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:12

Revision: reviewed by expert panel

Submissions by phenotype

not provided Pathogenic:4

Pathogenic, criteria provided, single submitter	clinical testing	CeGaT Center for Human Genetics Tuebingen	Jul 01, 2020	- -
Pathogenic, no assertion criteria provided	clinical testing	Department of Pathology and Laboratory Medicine, Sinai Health System	-	The BRCA2 p.Gln619X variant was not identified in the literature nor was it identified in the Cosmic, MutDB, UMD-LSDB, Zhejiang Colon Cancer Database, 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). The variant was identified in dbSNP (ID: rs80358476) “With Pathogenic allele”, ClinVar (classified pathogenic, reviewed by an expert panel (2016); submitters: ENIGMA, GeneDx, CIMB, Invitae, Ambry Genetics and BIC), Clinvitae (4x), LOVD 3.0 (1x), BIC Database (2x with clinical importance, class 5), and ARUP Laboratories (5-definitely pathogenic). The c.1855C>T variant leads to a premature stop codon at position 619 which is predicted to lead to a truncated or absent protein and loss of function. Loss of function variants of the BRCA2 gene are an established mechanism of disease in hereditary breast and ovarian cancer and is the type of variant expected to cause the disorder. In summary, based on the above information this variant meets our laboratory’s criteria to be classified as pathogenic. -
Pathogenic, criteria provided, single submitter	clinical testing	Quest Diagnostics Nichols Institute San Juan Capistrano	Jun 28, 2018	- -
Pathogenic, criteria provided, single submitter	clinical testing	GeneDx	Oct 11, 2018	This pathogenic variant is denoted BRCA2 c.1855C>T at the cDNA level and p.Gln619Ter (Q619X) at the protein level. The substitution creates a nonsense variant, which changes a Glutamine to a premature stop codon (CAG>TAG), and is predicted to cause loss of normal protein function through either protein truncation or nonsense-mediated mRNA decay. This variant, also published as BRCA2 2083C>T using alternate nomenclature, has been reported in at least one individual with breast cancer (Rashid 2006) and is considered pathogenic. -

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

Pathogenic, reviewed by expert panel	curation	Evidence-based Network for the Interpretation of Germline Mutant Alleles (ENIGMA)	Sep 08, 2016	Variant allele predicted to encode a truncated non-functional protein. -
Pathogenic, no assertion criteria provided	clinical testing	Breast Cancer Information Core (BIC) (BRCA2)	May 29, 2002	- -
Pathogenic, criteria provided, single submitter	clinical testing	Consortium of Investigators of Modifiers of BRCA1/2 (CIMBA), c/o University of Cambridge	Oct 02, 2015	- -

Hereditary cancer-predisposing syndrome Pathogenic:2

Pathogenic, criteria provided, single submitter	clinical testing	Ambry Genetics	Feb 14, 2022	The p.Q619* pathogenic mutation (also known as c.1855C>T), located in coding exon 9 of the BRCA2 gene, results from a C to T substitution at nucleotide position 1855. This changes the amino acid from a glutamine to a stop codon within coding exon 9. This mutation has been identified in multiple hereditary breast and ovarian cancer (HBOC) families (Rashid MU et al. Int. J. Cancer, 2006 Dec;119:2832-9; Rebbeck TR et al. Hum Mutat 2018 May;39(5):593-620; Dorling et al. N Engl J Med. 2021 02;384:428-439; Lerner-Ellis J et al. J Cancer Res Clin Oncol, 2021 Mar;147:871-879). In addition to the clinical data presented in the literature, this alteration is expected to result in loss of function by premature protein truncation or nonsense-mediated mRNA decay. As such, this alteration is interpreted as a disease-causing mutation. -
Pathogenic, criteria provided, single submitter	clinical testing	Color Diagnostics, LLC DBA Color Health	Sep 01, 2021	This variant changes 1 nucleotide in exon 10 of the BRCA2 gene, creating a premature translation stop signal. This variant has been identified in at least two individuals affected with breast and/or ovarian cancer (PMID: 16998791, 33471991; Leiden Open Variation Database DB-ID BRCA2_004289). This variant has not been identified in the general population by the Genome Aggregation Database (gnomAD). Loss of BRCA2 function is a known mechanism of disease (clinicalgenome.org). Based on the available evidence, this variant is classified as Pathogenic. -

Hereditary breast ovarian cancer syndrome Pathogenic:2

Pathogenic, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Aug 03, 2023	For these reasons, this variant has been classified as Pathogenic. ClinVar contains an entry for this variant (Variation ID: 51216). This variant is also known as 2083C>T. This premature translational stop signal has been observed in individual(s) with breast and/or ovarian cancer (PMID: 16998791, 21559243, 29470806, 29487695). This variant is not present in population databases (gnomAD no frequency). This sequence change creates a premature translational stop signal (p.Gln619*) in the BRCA2 gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in BRCA2 are known to be pathogenic (PMID: 20104584). -
Pathogenic, criteria provided, single submitter	clinical testing	Women's Health and Genetics/Laboratory Corporation of America, LabCorp	Jan 29, 2016	- -

BRCA2-related disorder Pathogenic:1

Pathogenic, no assertion criteria provided

clinical testing

PreventionGenetics, part of Exact Sciences

Sep 25, 2024

The BRCA2 c.1855C>T variant is predicted to result in premature protein termination (p.Gln619*). This variant was reported in individuals and families with breast and/or ovarian cancer (see for example: Rashid et al. 2006. PubMed ID: 16998791; Rebbeck et al. 2018. PubMed ID: 29446198; Lerner-Ellis et al. 2020. PubMed ID: 32885271). This variant has not been reported in a large population database, indicating this variant is rare. This variant is interpreted as pathogenic by many labs in ClinVar (https://www.ncbi.nlm.nih.gov/clinvar/variation/51216/). Nonsense variants in BRCA2 are expected to be pathogenic. This variant is interpreted as pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.40	D
BayesDel_noAF	Pathogenic	0.33
CADD	Pathogenic	32
DANN	Uncertain	1.0
Eigen	Uncertain	0.37
Eigen_PC	Benign	0.090
FATHMM_MKL	Benign	0.11	N
Vest4		0.87
GERP RS		5.5

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: rs80358476; hg19: chr13-32907470;