Our verdict is Pathogenic. The variant received 18 ACMG points: 18P and 0B. PVS1PM2PP5_Very_Strong
The NM_007294.4(BRCA1):c.4903G>T(p.Glu1635*) variant causes a stop gained change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Pathogenic (★★★). Synonymous variant affecting the same amino acid position (i.e. E1635E) has been classified as Uncertain significance. 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 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 17-43071011-C-A is Pathogenic according to our data. Variant chr17-43071011-C-A is described in ClinVar as Pathogenic. ClinVar VariationId is 55311.Status of the report is reviewed_by_expert_panel, 3 stars.
Breast-ovarian cancer, familial, susceptibility to, 1Pathogenic:2Uncertain:1
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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Feb 20, 2013
Breast Cancer Information Core (BIC) (BRCA1)
Significance:Uncertain significance
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 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
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Nov 28, 2023
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.Glu1635*) 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 breast and/or ovarian cancer (PMID: 22970155). ClinVar contains an entry for this variant (Variation ID: 55311). For these reasons, this variant has been classified as Pathogenic. -
The p.E1635* pathogenic mutation (also known as c.4903G>T), located in coding exon 14 of the BRCA1 gene, results from a G to T substitution at nucleotide position 4903. This changes the amino acid from a glutamic acid to a stop codon within coding exon 14. This mutation was previously identified in a breast and ovarian cancer family of Southern Chinese ancestry (Kwong A et al. PLoS ONE 2012; 7:e43994). This alteration 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). 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. -