Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PVS1PM2PP5_Very_Strong
The NM_007294.4(BRCA1):c.2709_2710del(p.Cys903Ter) variant causes a stop gained, 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 17-43092820-TCA-T is Pathogenic according to our data. Variant chr17-43092820-TCA-T is described in ClinVar as [Pathogenic]. Clinvar id is 266296.Status of the report is reviewed_by_expert_panel, 3 stars. Variant chr17-43092820-TCA-T is described in Lovd as [Pathogenic]. Variant chr17-43092820-TCA-T is described in Lovd as [Pathogenic].
Quest Diagnostics Nichols Institute San Juan Capistrano
Jun 15, 2018
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Pathogenic, criteria provided, single submitter
clinical testing
GeneDx
Jan 31, 2018
This variant is denoted BRCA1 c.2709_2710delTG at the cDNA level and p.Cys903Ter (C903X) at the protein level. The substitution creates a nonsense variant, which changes a Cysteine to a premature stop codon (TGT>TGA), and is predicted to cause loss of normal protein function through either protein truncation or nonsense-mediated mRNA decay. This variant has been reported in at least one family with hereditary risk for breast cancer (Lecarpentier 2012) and is considered pathogenic. -
Likely pathogenic, criteria provided, single submitter
clinical testing
Revvity Omics, Revvity
Sep 29, 2022
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Breast-ovarian cancer, familial, susceptibility to, 1 Pathogenic:2
Pathogenic, criteria provided, single submitter
clinical testing
Consortium of Investigators of Modifiers of BRCA1/2 (CIMBA), c/o University of Cambridge
Oct 02, 2015
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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. -
The c.2709_2710delTG pathogenic mutation, located in coding exon 9 of the BRCA1 gene, results from a deletion of two nucleotides at nucleotide positions 2709 to 2710, causing a translational frameshift with a predicted alternate stop codon (p.C903*). This mutation has been identified heterozygous in an HBOC cohort and homozygous in an individual who presented with a Fanconi anemia-like phenotype (Lecarpentier J et al. Breast Cancer Res, 2012 Jul;14:R99; Freire BL et al. Eur J Med Genet, 2018 Mar;61:130-133). In addition, 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. -
Hereditary breast ovarian cancer syndrome Pathogenic:1
Pathogenic, criteria provided, single submitter
clinical testing
Labcorp Genetics (formerly Invitae), Labcorp
Jul 15, 2020
This sequence change creates a premature translational stop signal (p.Cys903*) in the BRCA1 gene. It is expected to result in an absent or disrupted protein product. This variant is not present in population databases (ExAC no frequency). This variant has been observed in an individual with a personal and/or family history of breast or ovarian cancer (PMID: 24549055). ClinVar contains an entry for this variant (Variation ID: 266296). Loss-of-function variants in BRCA1 are known to be pathogenic (PMID: 20104584). For these reasons, this variant has been classified as Pathogenic. -