Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PVS1PM2PP5_Very_Strong
The NM_007294.4(BRCA1):c.3761_3762insTT(p.Lys1254AsnfsTer2) 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 17-43091769-C-CAA is Pathogenic according to our data. Variant chr17-43091769-C-CAA is described in ClinVar as [Pathogenic]. Clinvar id is 91614.Status of the report is reviewed_by_expert_panel, 3 stars.
Breast-ovarian cancer, familial, susceptibility to, 1 Pathogenic:6
Oct 02, 2015
Consortium of Investigators of Modifiers of BRCA1/2 (CIMBA), c/o University of Cambridge
Significance: Pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing
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May 29, 2002
Breast Cancer Information Core (BIC) (BRCA1)
Significance: Pathogenic
Review Status: no assertion criteria provided
Collection Method: clinical testing
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May 01, 2012
Sharing Clinical Reports Project (SCRP)
Significance: Pathogenic
Review Status: no assertion criteria provided
Collection Method: clinical testing
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Sep 08, 2016
Evidence-based Network for the Interpretation of Germline Mutant Alleles (ENIGMA)
Significance: Pathogenic
Review Status: reviewed by expert panel
Collection Method: curation
Variant allele predicted to encode a truncated non-functional protein. -
Apr 01, 2015
Quest Diagnostics Nichols Institute San Juan Capistrano
Significance: Pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing
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Jan 08, 2024
All of Us Research Program, National Institutes of Health
Significance: Pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing
This variant inserts 2 nucleotides in exon 10 of the BRCA1 gene, creating a frameshift and premature translation stop signal. This variant is expected to result in an absent or non-functional protein product. To our knowledge, this variant has not been reported in individuals affected with BRCA1-related disorders in the literature. This variant has not been identified in the general population by the Genome Aggregation Database (gnomAD). Loss of BRCA1 function is a known mechanism of disease (clinicalgenome.org). Based on the available evidence, this variant is classified as Pathogenic. -
Hereditary breast ovarian cancer syndrome Pathogenic:2
Apr 08, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance: Pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing
This sequence change creates a premature translational stop signal (p.Lys1254Asnfs*2) 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 personal and/or family history of breast and/or ovarian cancer (PMID: 29446198). This variant is also known as 3880insTT. ClinVar contains an entry for this variant (Variation ID: 91614). For these reasons, this variant has been classified as Pathogenic. -
Jan 31, 2014
Research Molecular Genetics Laboratory, Women's College Hospital, University of Toronto
Review Status: criteria provided, single submitter
Collection Method: clinical testing
The c.3761_3762insTT pathogenic mutation, located in coding exon 9 of the BRCA1 gene, results from an insertion of two nucleotides at position 3761, causing a translational frameshift with a predicted alternate stop codon (p.K1254Nfs*2). 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. -