13-32363217-TAA-TA
Variant summary
Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PVS1PM2PP5_Very_Strong
The NM_000059.4(BRCA2):c.8021delA(p.Lys2674ArgfsTer2) 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
Consequence
NM_000059.4 frameshift
Scores
Clinical Significance
Conservation
Genome browser will be placed here
ACMG classification
Verdict is Pathogenic. Variant got 18 ACMG points.
Transcripts
RefSeq
Ensembl
Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | TSL | MANE | Protein | Appris | UniProt |
---|---|---|---|---|---|---|---|---|---|---|
BRCA2 | ENST00000380152.8 | c.8021delA | p.Lys2674ArgfsTer2 | frameshift_variant | Exon 18 of 27 | 5 | NM_000059.4 | ENSP00000369497.3 | ||
BRCA2 | ENST00000530893.7 | c.7652delA | p.Lys2551ArgfsTer2 | frameshift_variant | Exon 18 of 27 | 1 | ENSP00000499438.2 | |||
BRCA2 | ENST00000614259.2 | n.*79delA | non_coding_transcript_exon_variant | Exon 17 of 26 | 2 | ENSP00000506251.1 | ||||
BRCA2 | ENST00000614259 | n.*79delA | 3_prime_UTR_variant | Exon 17 of 25 | 2 | ENSP00000506251.1 |
Frequencies
GnomAD3 genomes Cov.: 32
GnomAD4 exome Cov.: 31
GnomAD4 genome Cov.: 32
ClinVar
Submissions by phenotype
Breast-ovarian cancer, familial, susceptibility to, 2 Pathogenic:3
- -
Variant allele predicted to encode a truncated non-functional protein. -
- -
Hereditary breast ovarian cancer syndrome Pathogenic:3
This sequence change creates a premature translational stop signal (p.Lys2674Argfs*2) 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 BRCA2-related conditions (PMID: 21120943, 28664449, 28947987, 30702160). This variant is also known as 8020delA. ClinVar contains an entry for this variant (Variation ID: 52474). For these reasons, this variant has been classified as Pathogenic. -
Variant summary: BRCA2 c.8021delA (p.Lys2674ArgfsX2) 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 250930 control chromosomes (gnomAD). c.8021delA has been reported in the literature in multiple individuals affected with Hereditary Breast and Ovarian Cancer (Rebbeck_2018, Li_2017). 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. Two ClinVar submissions including an expert panel, ENIGMA, (evaluation after 2014) cite the variant as pathogenic. Based on the evidence outlined above, the variant was classified as pathogenic. -
The p.Lys2674ArgfsX2 variant in BRCA2 has been identified in at least 4 individuals with BRCA2-associated cancers (Caux-Moncoutier 2011 PMID: 21120943, Li 2017 PMID: 28664449, Solano 2017 PMID: 28947987, Bhaskaran 2019 PMID: 30702160), and in 6 individuals at increased risk of breast and/or ovarian cancer that have undergone genetic testing that includes BRCA1/2 (Tea 2014 PMID: 24156927, Rebbeck 2018 PMID:29446198). It was absent from large population studies (gnomAD, v.3.1.2). This variant is predicted to cause a frameshift, which alters the protein’s amino acid sequence beginning at position 2674 and leads to a premature termination codon 2 amino acids downstream. This alteration is then predicted to lead to a truncated or absent protein. Heterozygous loss of function of the BRCA2 gene is an established disease mechanism for hereditary breast and ovarian cancer (HBOC). Additionally, this variant was classified as pathogenic on Oct 18, 2016 by the ClinGen-approved ENIGMA expert panel (Variation ID: Variation ID 52474). In summary, this variant meets criteria to be classified as pathogenic for autosomal dominant HBOC. ACMG/AMP criteria applied: PS4_Moderate, PM2_Supporting, PVS1. -
Familial cancer of breast Pathogenic:1
- -
Hereditary cancer-predisposing syndrome Pathogenic:1
The c.8021delA pathogenic mutation, located in coding exon 17 of the BRCA2 gene, results from a deletion of one nucleotide at nucleotide position 8021, causing a translational frameshift with a predicted alternate stop codon (p.K2674Rfs*2). This alteration has been identified in patients of varying ancestries, including in a large, worldwide study of BRCA1/2 mutation positive families (Caux-Moncoutier V et al. Hum. Mutat., 2011 Mar;32:325-34; Li G et al. J. Cancer Res. Clin. Oncol., 2017 Oct;143:2011-2024; Rebbeck TR et al. Hum. Mutat., 2018 05;39:593-620; Solano AR et al. Oncotarget, 2017 Sep;8:60487-60495; Tea MK et al. Maturitas, 2014 Jan;77:68-72). This variant is considered to be rare based on population cohorts in the Genome Aggregation Database (gnomAD). 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. -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at