Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PVS1PM2PP5_Very_Strong
The NM_007294.4(BRCA1):c.1292delT(p.Leu431fs) 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.
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 17-43094238-TA-T is Pathogenic according to our data. Variant chr17-43094238-TA-T is described in ClinVar as [Pathogenic]. Clinvar id is 91543.Status of the report is reviewed_by_expert_panel, 3 stars. Variant chr17-43094238-TA-T is described in Lovd as [Pathogenic]. Variant chr17-43094238-TA-T is described in Lovd as [Pathogenic]. Variant chr17-43094238-TA-T is described in Lovd as [Pathogenic]. Variant chr17-43094238-TA-T is described in Lovd as [Pathogenic].
Breast-ovarian cancer, familial, susceptibility to, 1 Pathogenic:2
Pathogenic, no assertion criteria provided
clinical testing
Sharing Clinical Reports Project (SCRP)
Jan 24, 2008
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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:2
Pathogenic, criteria provided, single submitter
clinical testing
Labcorp Genetics (formerly Invitae), Labcorp
Jun 03, 2022
For these reasons, this variant has been classified as Pathogenic. ClinVar contains an entry for this variant (Variation ID: 91543). This variant has not been reported in the literature in individuals affected with BRCA1-related conditions. This variant is not present in population databases (gnomAD no frequency). This sequence change creates a premature translational stop signal (p.Leu431Tyrfs*10) 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). -
Likely pathogenic, criteria provided, single submitter
clinical testing
Women's Health and Genetics/Laboratory Corporation of America, LabCorp
Jul 24, 2017
Variant summary: The BRCA1 c.1292delT (p.Leu431Tyrfs) variant results in a premature termination codon, predicted to cause a truncated or absent BRCA1 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. p.Glu1470X, p.Glu1535X, p.Tyr1703X, etc.). This variant has been reported in multiple individuals undergoing clinical testing of BRCA1/2 by clinical laboratories and during validation of assay methods (van der Stoep_2009, Mattocks_2010). This variant is absent in 121238 control chromosomes from ExAC. In addition, multiple clinical diagnostic laboratories/reputable databases have classified this variant as pathogenic. Taken together, this variant is classified as likely pathogenic. -
The c.1292delT pathogenic mutation, located in coding exon 9 of the BRCA1 gene, results from a deletion of one nucleotide at nucleotide position 1292, causing a translational frameshift with a predicted alternate stop codon (p.L431Yfs*10). This variant is considered to be rare based on population cohorts in the Genome Aggregation Database (gnomAD). 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. -