Our verdict is Likely pathogenic. Variant got 6 ACMG points: 6P and 0B. PM1PM2PP3_Moderate
The NM_007294.4(BRCA1):c.5444G>C(p.Trp1815Ser) variant causes a missense change. The variant allele was found at a frequency of 0.00000205 in 1,461,892 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★).
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]
Review Status: criteria provided, single submitter
Collection Method: clinical testing
This missense variant replaces tryptophan with serine at codon 1815 of the BRCA1 protein. Computational prediction suggests that this variant may have deleterious impact on protein structure and function (internally defined REVEL score threshold >= 0.7, PMID: 27666373). This variant has been reported to result in the loss of BRCA1 protein function in a haploid cell proliferation assay (PMID: 30209399). To our knowledge, this variant has not been reported in individuals affected with BRCA1-related disorders in the literature. This variant has been identified in 1/251486 chromosomes in the general population by the Genome Aggregation Database (gnomAD). The available evidence is insufficient to determine the role of this variant in disease conclusively. Therefore, this variant is classified as a Variant of Uncertain Significance. -
Mar 08, 2024
Ambry Genetics
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing
The p.W1815S variant (also known as c.5444G>C), located in coding exon 21 of the BRCA1 gene, results from a G to C substitution at nucleotide position 5444. The tryptophan at codon 1815 is replaced by serine, an amino acid with highly dissimilar properties. One functional study found that this nucleotide substitution is non-functional in a high-throughput, genome editing, haploid cell survival assay (Findlay GM et al. Nature, 2018 10;562:217-222). In another study, this variant was found to be functional in homology-directed repair and cisplatin resistance, however these assays assessed only the protein change and did not incorporate any splicing impact, therefore this alteration was still reported as having overall loss-of-function due to the deleterious impact observed in saturation genome editing (SGE) assays (Adamovich AI et al. Am J Hum Genet. 2022 Apr;109(4):618-630). This amino acid position is highly conserved in available vertebrate species. In addition, this alteration is predicted to be deleterious by in silico analysis. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -
Breast-ovarian cancer, familial, susceptibility to, 1 Uncertain:1Other:1
Aug 15, 2023
All of Us Research Program, National Institutes of Health
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing
This missense variant replaces tryptophan with serine at codon 1815 of the BRCA1 protein. Computational prediction suggests that this variant may have deleterious impact on protein structure and function (internally defined REVEL score threshold >= 0.7, PMID: 27666373). This variant has been reported to result in the loss of BRCA1 protein function in a haploid cell proliferation assay (PMID: 30209399). To our knowledge, this variant has not been reported in individuals affected with BRCA1-related disorders in the literature. This variant has been identified in 1/251486 chromosomes in the general population by the Genome Aggregation Database (gnomAD). The available evidence is insufficient to determine the role of this variant in disease conclusively. Therefore, this variant is classified as a Variant of Uncertain Significance. -
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Brotman Baty Institute, University of Washington
Significance: not provided
Review Status: no classification provided
Collection Method: in vitro
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not specified Uncertain:1
Nov 25, 2022
Women's Health and Genetics/Laboratory Corporation of America, LabCorp
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing
Variant summary: BRCA1 c.5444G>C (p.Trp1815Ser) results in a non-conservative amino acid change located in the breast cancer carboxy-terminal (BRCT) domain of the encoded protein sequence. Four of five in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 4e-06 in 251486 control chromosomes. The available data on variant occurrences in the general population are insufficient to allow any conclusion about variant significance. To our knowledge, no occurrence of c.5444G>C in individuals affected with Hereditary Breast And Ovarian Cancer Syndrome has been reported. At least one publication reports experimental evidence evaluating an impact on protein function suggesting the variant may lead to loss of protein function, however, does not allow convincing conclusions to be made about the variant effect (Findlay_2018). Three clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014 without evidence for independent evaluation. All laboratories classified the variant as uncertain significance. Based on the evidence outlined above, the variant was classified as uncertain significance. -
Hereditary breast ovarian cancer syndrome Uncertain:1
Aug 08, 2022
Labcorp Genetics (formerly Invitae), Labcorp
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing
This sequence change replaces tryptophan, which is neutral and slightly polar, with serine, which is neutral and polar, at codon 1815 of the BRCA1 protein (p.Trp1815Ser). This variant is not present in population databases (gnomAD no frequency). This variant has not been reported in the literature in individuals affected with BRCA1-related conditions. ClinVar contains an entry for this variant (Variation ID: 566786). Advanced modeling of experimental studies (such as gene expression, population dynamics, functional pathways, and cell-cycle effects in cell culture) performed at Invitae indicates that this missense variant is expected to disrupt BRCA1 protein function. Experimental studies have shown that this missense change affects BRCA1 function (PMID: 30209399). In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -