chr13-32337424-CATT-C

Position:

• chr13-32337424-CATT-C

Variant summary

Our verdict is Uncertain significance. Variant got 1 ACMG points: 1P and 0B. PM4_Supporting

The NM_000059.4(BRCA2):​c.3071_3073del​(p.Ile1024del) variant causes a inframe deletion change. The variant allele was found at a frequency of 0.00000479 in 1,460,798 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★★).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000048 (0 hom.)
• Consequence: BRCA2 NM_000059.4 inframe_deletion
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:7
• Conservation: PhyloP100: 4.34

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 1 ACMG points.

• PM4: Nonframeshift variant in NON repetitive region in NM_000059.4. Strenght limited to Supporting due to length of the change: 1aa.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
BRCA2	NM_000059.4	c.3071_3073del	p.Ile1024del	inframe_deletion	11/27	ENST00000380152.8	NP_000050.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
BRCA2	ENST00000380152.8	c.3071_3073del	p.Ile1024del	inframe_deletion	11/27	5	NM_000059.4	ENSP00000369497	A2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD3 exomes AF: 0.00000400 AC: 1 AN: 250134 Hom.: 0 AF XY: 0.00000739 AC XY: 1 AN XY: 135318

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: 0.00000884

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000479 AC: 7 AN: 1460798 Hom.: 0 AF XY: 0.00000550 AC XY: 4 AN XY: 726682

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: 0.00000630

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:7

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

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

Uncertain significance, criteria provided, single submitter	clinical testing	Quest Diagnostics Nichols Institute San Juan Capistrano	Mar 31, 2016	- -
Uncertain significance, criteria provided, single submitter	clinical testing	St. Jude Molecular Pathology, St. Jude Children's Research Hospital	Apr 14, 2023	The BRCA2 c.3071_3073del (p.Ile1024del) change deletes three nucleotides at position 3071-3073 resulting in an in-frame deletion of one amino acid at codon 1024 in exon 11. This change has a maximum subpopulation frequency of 0.00088% in gnomAD v2.1.1 (https://gnomad.broadinstitute.org/). It is absent in a database of women older than 70 years of age who have never had cancer (FLOSSIES, https://whi.color.com/). To our knowledge, this variant has not been reported in individuals with BRCA2-associated conditions. In summary, the evidence currently available is insufficient to determine the clinical significance of this variant. It has therefore been classified as of uncertain significance. -

Hereditary cancer-predisposing syndrome Uncertain:2

Uncertain significance, criteria provided, single submitter	clinical testing	Color Diagnostics, LLC DBA Color Health	Dec 07, 2021	This variant causes an in-frame deletion of one amino acid, Isoleucine 1024, in the BRCA2 protein. A multifactorial analysis has reported co-occurrence and family history likelihood ratios for pathogenicity of 1.0246 and 0.2272, respectively (PMID: 31131967). This variant has been identified in 1/250134 chromosomes 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. -
Uncertain significance, criteria provided, single submitter	clinical testing	Ambry Genetics	Mar 15, 2018	The c.3071_3073delTTA variant (also known as p.I1024del) is located in coding exon 10 of the BRCA2 gene. This variant results from an in-frame TTA deletion at nucleotide positions 3071 to 3073. This results in the in-frame deletion of an isoleucine at codon 1024. The deleted amino acid position is not well conserved in available vertebrate species. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -

not provided Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

GeneDx

Oct 28, 2019

In-frame deletion of one amino acid in a non-repeat region; Not observed at a significant frequency in large population cohorts (Lek et al., 2016); In silico analysis, which includes protein predictors and evolutionary conservation, supports a deleterious effect; Also known as BRCA2 3299_3301delTTA; This variant is associated with the following publications: (PMID: 31131967) -

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.Ile1024del variant was identified in the ClinVar database, it was submitted and classified as a variant of uncertain significance by Ambry Genetics. The variant was not identified in the literature, nor was it identified in any other database searches (dbSNP, NHLBI Exome Sequencing Project (Exome Variant Server), Exome Aggregation Consortium (ExAC) database, Clinvitae database, LOVD, ARUP Laboratories BRCA Mutations Database, COSMIC, BIC database, GeneInsight COGR database). The variant is an in-frame deletion resulting in the removal of an isoleucine (Ile) residue at codon 1024; the impact of this alteration on BRCA2 protein function is not known. In summary, based on the above information, the clinical significance of this variant cannot be determined with certainty at this time. This variant is classified as a variant of unknown significance. -

Hereditary breast ovarian cancer syndrome Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Jul 21, 2021

In summary, this variant is a rare in-frame deletion with uncertain impact on protein function. There is no indication that it causes disease, but the available evidence is currently insufficient to prove that conclusively. Therefore, it has been classified as a Variant of Uncertain Significance. Experimental studies and prediction algorithms are not available for this variant, and the functional significance of the deleted amino acid is currently unknown. This variant has not been reported in the literature in individuals with a BRCA2-related disease. ClinVar contains an entry for this variant (Variation ID: 187582). This variant is present in population databases (rs754836679, ExAC 0.002%). This sequence change deletes 3 nucleotides from exon 11 of the BRCA2 mRNA (c.3071_3073delTTA). This leads to the deletion of 1 amino acid residue in the BRCA2 protein (p.Ile1024del) but otherwise preserves the integrity of the reading frame. -

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: rs754836679; hg19: chr13-32911561;