13-32337717-C-G

Position:

• chr13-32337717-C-G

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.3362C>G​(p.Ser1121Ter) variant causes a stop gained change. The variant allele was found at a frequency of 0.00000205 in 1,460,788 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: 0.0000021 (0 hom.)
• Consequence: BRCA2 NM_000059.4 stop_gained
• Clinical Significance: Pathogenic reviewed by expert panel P:12
• Conservation: PhyloP100: 5.86

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 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 13-32337717-C-G is Pathogenic according to our data. Variant chr13-32337717-C-G is described in ClinVar as [Pathogenic]. Clinvar id is 51453.Status of the report is reviewed_by_expert_panel, 3 stars. Variant chr13-32337717-C-G is described in Lovd as [Pathogenic]. Variant chr13-32337717-C-G is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
BRCA2	NM_000059.4	c.3362C>G	p.Ser1121Ter	stop_gained	11/27	ENST00000380152.8	NP_000050.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
BRCA2	ENST00000380152.8	c.3362C>G	p.Ser1121Ter	stop_gained	11/27	5	NM_000059.4	ENSP00000369497	A2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000205 AC: 3 AN: 1460788 Hom.: 0 Cov.: 33 AF XY: 0.00000275 AC XY: 2 AN XY: 726638

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: 0.0000349

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

Breast-ovarian cancer, familial, susceptibility to, 2 Pathogenic:4

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, criteria provided, single submitter	clinical testing	Consortium of Investigators of Modifiers of BRCA1/2 (CIMBA), c/o University of Cambridge	Oct 02, 2015	- -
Pathogenic, no assertion criteria provided	clinical testing	Breast Cancer Information Core (BIC) (BRCA2)	May 29, 2002	- -
Pathogenic, no assertion criteria provided	clinical testing	Sharing Clinical Reports Project (SCRP)	Dec 12, 2008	- -

not provided Pathogenic:2

Pathogenic, criteria provided, single submitter	clinical testing	GeneDx	Sep 12, 2018	This pathogenic variant is denoted BRCA2 c.3362C>G at the cDNA level and p.Ser1121Ter (S1121X) at the protein level. This variant is also known as BRCA2 3590C>G using alternate nomenclature. The substitution creates a nonsense variant, which changes a Serine to a premature stop codon (TCA>TGA), and is predicted to cause loss of normal protein function through either protein truncation or nonsense-mediated mRNA decay. This variant has been reported in a large cohort of self-identified Ashkenazi Jewish women with hereditary breast and/or ovarian cancer as well as in two affected members of a Filipino family with early-onset breast cancer (De Leon 2002, Finkelman 2012). We consider this variant to be pathogenic. -
Pathogenic, criteria provided, single submitter	clinical testing	Quest Diagnostics Nichols Institute San Juan Capistrano	Sep 12, 2019	The variant creates a premature nonsense codon, and is therefore predicted to result in the loss of a functional protein. Found in at least one patient with expected phenotype for this gene, and not found in general population data. -

Hereditary cancer-predisposing syndrome Pathogenic:2

Pathogenic, criteria provided, single submitter	clinical testing	Color Diagnostics, LLC DBA Color Health	Jan 15, 2020	This variant changes 1 nucleotide in exon 11 of the BRCA2 gene, creating a premature translation stop signal. This variant is expected to result in an absent or non-functional protein product. 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. -
Pathogenic, criteria provided, single submitter	clinical testing	Ambry Genetics	Aug 27, 2023	The p.S1121* pathogenic mutation (also known as c.3362C>G or 3590C>G), located in coding exon 10 of the BRCA2 gene, results from a C to G substitution at nucleotide position 3362. This changes the amino acid from a serine to a stop codon within coding exon 10. This mutation has been reported in two sisters from the Philippines who were diagnosed with breast cancer at ages 43 and 45, and whose family history included early onset breast cancer and brain tumors (De Leon M et al. Int J Cancer. 2002 Apr 1;98(4):596-603). In addition, this alteration was identified in a large, worldwide study of BRCA1/2 mutation positive families (Rebbeck TR et al. Hum Mutat. 2018 May;39(5):593-620). 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. -

Hereditary breast ovarian cancer syndrome Pathogenic:2

Pathogenic, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Jan 05, 2024	This sequence change creates a premature translational stop signal (p.Ser1121*) 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). This variant is not present in population databases (gnomAD no frequency). This premature translational stop signal has been observed in individual(s) with breast cancer (PMID: 11920621, 28288110). This variant is also known as 3590C>G. ClinVar contains an entry for this variant (Variation ID: 51453). For these reasons, this variant has been classified as Pathogenic. -
Pathogenic, criteria provided, single submitter	clinical testing	Women's Health and Genetics/Laboratory Corporation of America, LabCorp	Nov 15, 2019	Variant summary: BRCA2 c.3362C>G (p.Ser1121X) results in a premature termination codon, predicted to cause a truncation of the encoded protein or absence of the protein due to nonsense mediated decay, which are commonly known mechanisms for disease. Truncations downstream of this position have been classified as pathogenic by our laboratory. The variant was absent in 250192 control chromosomes. c.3362C>G has been reported in the literature in individuals affected with Hereditary Breast and Ovarian Cancer, including two affected family members (De Leon Matsuda_2002, Finkelman_2012, Rebbeck_2018). These data indicate that the variant is likely to be associated with disease. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. Five clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014 without evidence for independent evaluation. All laboratories classified the variant as pathogenic. Based on the evidence outlined above, the variant was classified as pathogenic. -

Malignant tumor of breast Pathogenic:1

Pathogenic, no assertion criteria provided

clinical testing

Department of Pathology and Laboratory Medicine, Sinai Health System

-

The BRCA2 p.Ser1121X variant was identified by De Leon Matsuda (2002) in two Filipino sisters with breast cancer, and was not detected in control subjects. The variant was also identified in dbSNP (ID: rs80358579) “With pathogenic allele”, HGMD, and the BIC database (4X with clinical importance). In addition, a different variant with the same change at the protein level (c.3362C>A, p.Ser1121X) was listed twice in UMD as a causal variant and once in the BIC database as a variant with clinical importance. The p.Ser1121X variant leads to a premature stop codon at position 1121, 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. -

Familial cancer of breast Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Baylor Genetics

Aug 04, 2023

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.62	D
BayesDel_noAF	Pathogenic	0.65
CADD	Pathogenic	38
DANN	Uncertain	1.0
Eigen	Pathogenic	1.2
Eigen_PC	Pathogenic	1.0
FATHMM_MKL	Pathogenic	0.98	D
MutationTaster	Benign	1.0	A;A
Vest4		0.89
GERP RS		5.8

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: rs80358579; hg19: chr13-32911854;