Our verdict is Pathogenic. The variant received 19 ACMG points: 19P and 0B. PVS1PM2PP3PP5_Very_Strong
The NM_007294.4(BRCA1):c.4186C>T(p.Gln1396*) variant causes a stop gained, splice region change. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. 2/3 splice prediction tools predicting alterations to normal splicing. 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]
BRCA1 Gene-Disease associations (from GenCC):
breast-ovarian cancer, familial, susceptibility to, 1
Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: Ambry Genetics, ClinGen, Labcorp Genetics (formerly Invitae), Genomics England PanelApp
Our verdict: Pathogenic. The variant received 19 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;
PP3
Splicing predictors support a deleterious effect. Scorers claiming Pathogenic: dbscSNV1_ADA, dbscSNV1_RF. No scorers claiming Uncertain. Scorers claiming Benign: max_spliceai.
PP5
Variant 17-43082575-G-A is Pathogenic according to our data. Variant chr17-43082575-G-A is described in ClinVar as Pathogenic. ClinVar VariationId is 55135.Status of the report is reviewed_by_expert_panel, 3 stars.
Breast-ovarian cancer, familial, susceptibility to, 1Pathogenic:5
Jun 22, 1999
Breast Cancer Information Core (BIC) (BRCA1)
Significance:Pathogenic
Review Status:no assertion criteria provided
Collection Method:clinical testing
Jul 01, 2015
Department of Medical Genetics, Oslo University Hospital
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing
Dec 15, 2017
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.
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
Aug 26, 2022
BRCAlab, Lund University
Significance:Pathogenic
Review Status:no assertion criteria provided
Collection Method:clinical testing
Hereditary breast ovarian cancer syndromePathogenic:2
Jan 31, 2014
Research Molecular Genetics Laboratory, Women's College Hospital, University of Toronto
Significance:Pathogenic
Review Status:no assertion criteria provided
Collection Method:research
Apr 04, 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. Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. ClinVar contains an entry for this variant (Variation ID: 55135). This premature translational stop signal has been observed in individual(s) with breast cancer (PMID: 12585668, 25682074). This variant is not present in population databases (gnomAD no frequency). This sequence change creates a premature translational stop signal (p.Gln1396*) 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).
not providedPathogenic:1
Nov 14, 2017
Quest Diagnostics Nichols Institute San Juan Capistrano
The p.Q1396* pathogenic mutation (also known as c.4186C>T), located in coding exon 11 of the BRCA1 gene, results from a C to T substitution at nucleotide position 4186. This changes the amino acid from a glutamine to a stop codon within coding exon 11. In a large, clinic-based BRCA1/2 testing cohort in Norway, this mutation was detected in one family (Heramb C et al. Hered Cancer Clin Pract. 2018 Jan;16:3). This mutation was also identified in a large, worldwide study of BRCA1/2 mutation positive families (Rebbeck TR et al. Hum. Mutat. 2018 05;39:593-620). In another study, this mutation was detected in 1/774 women with triple-negative breast cancer, and the patient who carried this mutation also carried a BRCA2 mutation (Wong-Brown MW et al. Breast Cancer Res. Treat. 2015 Feb;150:71-80). This variant is considered to be rare based on population cohorts in the Genome Aggregation Database (gnomAD). 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.