Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PVS1PM2PP5_Very_Strong
The NM_007294.4(BRCA1):c.1700dupA(p.Asn567LysfsTer3) variant causes a frameshift change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,146 control chromosomes in the GnomAD database, with no homozygous occurrence. 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 17-43093830-A-AT is Pathogenic according to our data. Variant chr17-43093830-A-AT is described in ClinVar as [Pathogenic]. Clinvar id is 125508.Status of the report is reviewed_by_expert_panel, 3 stars.
Breast-ovarian cancer, familial, susceptibility to, 1 Pathogenic:2
Jun 20, 2002
Breast Cancer Information Core (BIC) (BRCA1)
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. -
Hereditary breast ovarian cancer syndrome Pathogenic:2
Aug 21, 2014
Department of Pathology and Laboratory Medicine, Sinai Health System
Significance: Pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing
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Jan 26, 2022
Labcorp Genetics (formerly Invitae), Labcorp
Significance: Pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing
For these reasons, this variant has been classified as Pathogenic. ClinVar contains an entry for this variant (Variation ID: 125508). This premature translational stop signal has been observed in individual(s) with breast, ovarian, or pancreatic cancer (PMID: 27882536). This variant is not present in population databases (gnomAD no frequency). This sequence change creates a premature translational stop signal (p.Asn567Lysfs*3) 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). -
Review Status: criteria provided, single submitter
Collection Method: clinical testing
The c.1700dupA pathogenic mutation, located in coding exon 9 of the BRCA1 gene, results from a duplication of A at nucleotide position 1700, causing a translational frameshift with a predicted alternate stop codon (p.N567Kfs*3). This alteration was identified in multiple individuals diagnosed with either breast, ovarian, or pancreatic cancer (Loizidou MA et al. Clin Genet, 2017 Apr;91:611-615; Jiang Y et al. Biomed Res Int, 2020 Aug;2020:6739823). 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. -