rs1555281459

Variant names:

• chr13-32330953-GTC-G
• rs1555281459
• NM_000059.4:c.718_719delCT

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.718_719delCT​(p.Leu240GlufsTer4) 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 Likely pathogenic (★★). Variant results in nonsense mediated mRNA decay.

• Frequency: Genomes: not found (cov: 32)
• Consequence: BRCA2 NM_000059.4 frameshift
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:2
• Conservation: PhyloP100: 0.485

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 13-32330953-GTC-G is Pathogenic according to our data. Variant chr13-32330953-GTC-G is described in ClinVar as [Likely_pathogenic]. Clinvar id is 495496.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
BRCA2	NM_000059.4	c.718_719delCT	p.Leu240GlufsTer4	frameshift_variant	Exon 9 of 27	ENST00000380152.8	NP_000050.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
BRCA2	ENST00000380152.8	c.718_719delCT	p.Leu240GlufsTer4	frameshift_variant	Exon 9 of 27	5	NM_000059.4	ENSP00000369497.3
BRCA2	ENST00000530893.7	c.349_350delCT	p.Leu117GlufsTer4	frameshift_variant	Exon 9 of 27	1		ENSP00000499438.2
BRCA2	ENST00000614259.2	n.718_719delCT		non_coding_transcript_exon_variant	Exon 8 of 26	2		ENSP00000506251.1

Frequencies

GnomAD3 genomes Cov.: 32

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

GnomAD4 genome Cov.: 32

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Hereditary breast ovarian cancer syndrome Pathogenic:2

Oct 03, 2016

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Variant summary: The BRCA2 c.718_719delCT (p.Leu240Glufs) variant results in a premature termination codon, predicted to cause a truncated or absent BRCA2 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 (e.g. c.755_758delACAG (p.Asp252fs), and c.778_779delGA (p.Glu260fs)). The variant of interest was not observed in controls (ExAC, 1000 Gs, or ESP), nor has it been, to our knowledge, reported in affected individuals via publications and/or reputable clinical diagnostic laboratories/databases. Therefore, taking all available lines of evidence into consideration, the variant of interest has been classified as likely pathogenic until additional information becomes available. -

Sep 26, 2019

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant has not been reported in the literature in individuals with BRCA2-related conditions. ClinVar contains an entry for this variant (Variation ID: 495496). This variant is not present in population databases (ExAC no frequency). This sequence change creates a premature translational stop signal (p.Leu240Glufs*4) 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). For these reasons, this variant has been classified as Pathogenic. -

Computational scores

Source: dbNSFP v4.3

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		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: rs1555281459; hg19: chr13-32905090;