Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PVS1PM2PP5_Very_Strong
The ENST00000357654.9(BRCA1):c.1374del(p.Asp458GlufsTer17) 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 (★★★). Synonymous variant affecting the same amino acid position (i.e. D458D) has been classified as Likely benign. Variant results in nonsense mediated mRNA decay.
BRCA1 (HGNC:1100): (BRCA1 DNA repair associated) This gene encodes a 190 kD nuclear phosphoprotein that plays a role in maintaining genomic stability, and it also acts as a tumor suppressor. The BRCA1 gene contains 22 exons spanning about 110 kb of DNA. The encoded protein combines with other tumor suppressors, DNA damage sensors, and signal transducers to form a large multi-subunit protein complex known as the BRCA1-associated genome surveillance complex (BASC). This gene product associates with RNA polymerase II, and through the C-terminal domain, also interacts with histone deacetylase complexes. This protein thus plays a role in transcription, DNA repair of double-stranded breaks, and recombination. Mutations in this gene are responsible for approximately 40% of inherited breast cancers and more than 80% of inherited breast and ovarian cancers. Alternative splicing plays a role in modulating the subcellular localization and physiological function of this gene. Many alternatively spliced transcript variants, some of which are disease-associated mutations, have been described for this gene, but the full-length natures of only some of these variants has been described. A related pseudogene, which is also located on chromosome 17, has been identified. [provided by RefSeq, May 2020]
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 17-43094156-TG-T is Pathogenic according to our data. Variant chr17-43094156-TG-T is described in ClinVar as [Pathogenic]. Clinvar id is 54224.Status of the report is reviewed_by_expert_panel, 3 stars. Variant chr17-43094156-TG-T is described in Lovd as [Pathogenic]. Variant chr17-43094156-TG-T is described in Lovd as [Pathogenic].
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
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Pathogenic, criteria provided, single submitter
clinical testing
Labcorp Genetics (formerly Invitae), Labcorp
Sep 26, 2023
This sequence change creates a premature translational stop signal (p.Asp458Glufs*17) in the BRCA1 gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in BRCA1 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, ovarian cancer and fallopian tube cancer (PMID: 15146556, 26915939, 29446198). This variant is also known as 1493delC. ClinVar contains an entry for this variant (Variation ID: 54224). 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
Dec 18, 2020
Variant summary: BRCA1 c.1374delC (p.Asp458GlufsX17) 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 251028 control chromosomes. c.1374delC has been reported in the literature in individuals affected with Hereditary Breast And Ovarian Cancer Syndrome (example, Rebbeck_2018). These data indicate that the variant is likely to be associated with disease. Three clinical diagnostic laboratories and one expert panel (ENIGMA) have submitted clinical-significance assessments for this variant to ClinVar after 2014 without evidence for independent evaluation. All submitters classified the variant as pathogenic. Based on the evidence outlined above, the variant was classified as pathogenic. -
Breast-ovarian cancer, familial, susceptibility to, 1 Pathogenic:2
Pathogenic, reviewed by expert panel
curation
Evidence-based Network for the Interpretation of Germline Mutant Alleles (ENIGMA)
Oct 18, 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
The c.1374delC pathogenic mutation, located in coding exon 9 of the BRCA1 gene, results from a deletion of one nucleotide at nucleotide position 1374, causing a translational frameshift with a predicted alternate stop codon (p.D458Efs*17). This mutation (also designated as 1493delC) has been identified in multiple high-risk breast/ovarian cancer families from South Africa and has been described as a common mutation in that population (Reeves MD et al. Int. J. Cancer, 2004 Jul;110:677-82; Schoeman M et al. S. Afr. Med. J., 2013 Jun;103:529-33). 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. -