chr13-32340123-ACATT-A

Position:

• chr13-32340123-ACATT-A

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.5771_5774delTTCA​(p.Ile1924fs) variant causes a frameshift change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Pathogenic (★★★). Variant results in nonsense mediated mRNA decay.

• Frequency: Genomes: not found (cov: 33)
• Consequence: BRCA2 NM_000059.4 frameshift
• Clinical Significance: Pathogenic reviewed by expert panel P:9
• Conservation: PhyloP100: 1.41

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 13-32340123-ACATT-A is Pathogenic according to our data. Variant chr13-32340123-ACATT-A is described in ClinVar as [Pathogenic]. Clinvar id is 51932.Status of the report is reviewed_by_expert_panel, 3 stars. Variant chr13-32340123-ACATT-A is described in Lovd as [Pathogenic]. Variant chr13-32340123-ACATT-A is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
BRCA2	NM_000059.4	c.5771_5774delTTCA	p.Ile1924fs	frameshift_variant	11/27	ENST00000380152.8	NP_000050.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
BRCA2	ENST00000380152.8	c.5771_5774delTTCA	p.Ile1924fs	frameshift_variant	11/27	5	NM_000059.4	ENSP00000369497.3
BRCA2	ENST00000530893.7	c.5402_5405delTTCA	p.Ile1801fs	frameshift_variant	11/27	1		ENSP00000499438.2
BRCA2	ENST00000614259.2	n.5771_5774delTTCA		non_coding_transcript_exon_variant	10/26	2		ENSP00000506251.1

Frequencies

GnomAD3 genomes Cov.: 33

We have no GnomAD4 exomes data on this position. Probably position not covered by the project.

GnomAD4 genome Cov.: 33

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:9

Revision: reviewed by expert panel

Submissions by phenotype

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

Pathogenic, no assertion criteria provided	clinical testing	Breast Cancer Information Core (BIC) (BRCA2)	-	- -
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, 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. -

Hereditary breast ovarian cancer syndrome Pathogenic:3

Pathogenic, criteria provided, single submitter	clinical testing	National Health Laboratory Service, Universitas Academic Hospital and University of the Free State	Apr 19, 2022	- -
Pathogenic, criteria provided, single submitter	clinical testing	Women's Health and Genetics/Laboratory Corporation of America, LabCorp	Oct 31, 2023	Variant summary: BBRCA2 c.5771_5774delTTCA (p.Ile1924ArgfsX38) 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. Variants downstream of this position have been classified as pathogenic by our laboratory. The variant was absent in 250518 control chromosomes. c.5771_5774delTTCA has been reported in the literature in multiple individuals affected with Hereditary Breast And Ovarian Cancer Syndrome (Teixeira_2018). These data indicate that the variant is very likely to be associated with disease. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. The following publication have been ascertained in the context of this evaluation (PMID: 29483665). Seven submitters have cited clinical-significance assessments for this variant to ClinVar after 2014. All submitters classified the variant as pathogenic. Based on the evidence outlined above, the variant was classified as pathogenic. -
Pathogenic, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Dec 18, 2023	This sequence change creates a premature translational stop signal (p.Ile1924Argfs*38) 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 Fanconi anemia (PMID: 21204799, 28185119, 30287823). This variant is also known as 5999del4. ClinVar contains an entry for this variant (Variation ID: 51932). For these reasons, this variant has been classified as Pathogenic. -

not provided Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

GeneDx

May 07, 2018

This deletion of four nucleotides in BRCA2 is denoted c.5771_5774delTTCA at the cDNA level and p.Ile1924ArgfsX38 (I1924RfsX38) at the protein level. Of note, using alternate nomenclature, this variant would be defined as BRCA2 5999del4 or 5999_6002delTTCA. The normal sequence, with the bases that are deleted in brackets, is GACA[delTTCA]GAGT. The deletion causes a frameshift which changes an Isoleucine to an Arginine at codon 1924, and creates a premature stop codon at position 38 of the new reading frame. This variant is predicted to cause loss of normal protein function through either protein truncation or nonsense-mediated mRNA decay. BRCA2 c.5771_5774delTTCA has been described as a founder pathogenic variant in South Africa and has been reported in the compound heterozygous state in at least two children with Fanconi Anemia (van der Merwe 2012, Francies 2015, Feben 2017). We consider this variant to be pathogenic. -

Hereditary cancer-predisposing syndrome Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Ambry Genetics

Mar 22, 2023

The c.5771_5774delTTCA pathogenic mutation, located in coding exon 10 of the BRCA2 gene, results from a deletion of 4 nucleotides at nucleotide positions 5771 to 5774, causing a translational frameshift with a predicted alternate stop codon (p.I1924Rfs*38). This alteration has been reported in multiple individuals with suspicion for hereditary breast and ovarian cancer syndrome and has been reported as a founder mutation from the Western Cape of South Africa (van der Merwe NC et al. Clin. Genet. 2012 Feb;81:179-84; Schoeman M et al. S. Afr. Med. J. 2013 Jun;103:529-33; Francies FZ et al. BMC Cancer 2015 Nov;15:912). 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. This variant is considered to be rare based on population cohorts in the Genome Aggregation Database (gnomAD). As such, this alteration is interpreted as a disease-causing mutation. -

Familial cancer of breast Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Laboratorio de Genetica e Diagnostico Molecular, Hospital Israelita Albert Einstein

Nov 25, 2022

ACMG classification criteria: PVS1 very strong, PS4 strong, PM2 moderated -

Computational scores

Source: dbNSFP v4.3

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: rs80359535; hg19: chr13-32914260;