Our verdict is Pathogenic. Variant got 14 ACMG points: 14P and 0B. PM1PM2PP3_ModeratePP5_Very_Strong
The NM_007294.4(BRCA1):c.5114T>C(p.Leu1705Pro) variant causes a missense change. 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 Likely pathogenic (★★).
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 14 ACMG points.
PM1
In a helix (size 7) in uniprot entity BRCA1_HUMAN there are 12 pathogenic changes around while only 2 benign (86%) in NM_007294.4
PM2
Very rare variant in population databases, with high coverage;
PP3
MetaRNN computational evidence supports a deleterious effect, 0.875
PP5
Variant 17-43063912-A-G is Pathogenic according to our data. Variant chr17-43063912-A-G is described in ClinVar as [Likely_pathogenic]. Clinvar id is 37637.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
Review Status: criteria provided, single submitter
Collection Method: clinical testing
The p.L1705P variant (also known as c.5114T>C), located in coding exon 16 of the BRCA1 gene, results from a T to C substitution at nucleotide position 5114. The leucine at codon 1705 is replaced by proline, an amino acid with similar properties. Functional transcription assays in yeast have shown that this variant abolishes transcription activation by the BRCA1 C-terminus (Hayes F et al. Cancer Res. 2000 May;60:2411-8). Another functional study found that this nucleotide substitution is deleterious in a high-throughput, genome editing, haploid cell-survival assay (Findlay GM et al. Nature. 2018 10;562:217-222). This variant was identified in a woman with contralateral, triple-negative breast cancer whose tumor showed loss of heterozygosity of the wild-type BRCA1 allele. Her breast-cancer-affected daughter and ovarian-cancer-affected sister also carried this variant (Sokolenko AP et al. Mol. Biol. Rep. 2016 May;43:335-8). Based on internal structural analysis, this variant is anticipated to result in a significant decrease in structural stability (Wu Q et al. Mol. Cell. 2016 Feb;61:434-448, Ambry internal data). This amino acid position is highly conserved in available vertebrate species. In addition, this alteration is predicted to be deleterious by in silico analysis. Based on the majority of available evidence to date, this variant is likely to be pathogenic. -
Hereditary breast ovarian cancer syndrome Pathogenic:1
Nov 19, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance: Pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing
This sequence change replaces leucine, which is neutral and non-polar, with proline, which is neutral and non-polar, at codon 1705 of the BRCA1 protein (p.Leu1705Pro). This variant is not present in population databases (gnomAD no frequency). This missense change has been observed in individual(s) with breast and ovarian cancer (PMID: 26951538; internal data). It has also been observed to segregate with disease in related individuals. ClinVar contains an entry for this variant (Variation ID: 37637). Invitae Evidence Modeling incorporating data from in vitro experimental studies (PMID: 30209399) indicates that this missense variant is expected to disrupt BRCA1 function with a positive predictive value of 95%. Experimental studies have shown that this missense change affects BRCA1 function (PMID: 10811118, 30209399). For these reasons, this variant has been classified as Pathogenic. -