Our verdict is Likely benign. Variant got -3 ACMG points: 2P and 5B. PM2BP4_StrongBP6
The NM_007294.4(BRCA1):āc.2657C>Gā(p.Ser886Cys) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000657 in 152,190 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 15/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. S886F) has been classified as Likely benign.
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 Likely_benign. Variant got -3 ACMG points.
PM2
Very rare variant in population databases, with high coverage;
BP4
Computational evidence support a benign effect (MetaRNN=0.023602933).
BP6
Variant 17-43092874-G-C is Benign according to our data. Variant chr17-43092874-G-C is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 141950.We mark this variant Likely_benign, oryginal submissions are: {Uncertain_significance=2, Likely_benign=2}.
Uncertain significance, criteria provided, single submitter
clinical testing
GeneDx
Nov 16, 2023
Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports that this missense variant does not alter protein structure/function; Has not been previously published as pathogenic or benign to our knowledge; Also known as 2776C>G; This variant is associated with the following publications: (PMID: 15343273, 29884841) -
Uncertain significance, no assertion criteria provided
clinical testing
Department of Pathology and Laboratory Medicine, Sinai Health System
-
The p.Ser886Cys variant was not identified in the literature. The variant was identified in UMD (1X as an unclassified variant), but was not identified in any of the other databases searched, including dbSNP, NHLBI Exome Sequencing Project (Exome Variant Server), HGMD, LOVD, COSMIC, and BIC. The p.Ser886 residue is not conserved in mammals and the variant amino acid cysteine (Cys) is present in dog, increasing the likelihood that this variant does not have clinical significance. Computational analyses (PolyPhen-2, SIFT, AlignGVGD, MutationTaster) do not suggest a high likelihood of impact to the protein; however, this information is not predictive enough to rule out pathogenicity. In summary, based on the above information, the clinical significance of this variant cannot be determined with certainty at this time. This variant is classified as a variant of unknown significance. -
Hereditary cancer-predisposing syndrome Benign:2
Likely benign, criteria provided, single submitter
clinical testing
Ambry Genetics
Dec 28, 2016
This alteration is classified as likely benign based on a combination of the following: seen in unaffected individuals, population frequency, intact protein function, lack of segregation with disease, co-occurrence, RNA analysis, in silico models, amino acid conservation, lack of disease association in case-control studies, and/or the mechanism of disease or impacted region is inconsistent with a known cause of pathogenicity. -
Likely benign, criteria provided, single submitter
curation
University of Washington Department of Laboratory Medicine, University of Washington
Mar 23, 2023
Missense variant in a coldspot region where missense variants are very unlikely to be pathogenic (PMID:31911673). -
Hereditary breast ovarian cancer syndrome Uncertain:1
Uncertain significance, criteria provided, single submitter
clinical testing
Invitae
Nov 06, 2023
This sequence change replaces serine, which is neutral and polar, with cysteine, which is neutral and slightly polar, at codon 886 of the BRCA1 protein (p.Ser886Cys). 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: 141950). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is not expected to disrupt BRCA1 protein function with a negative predictive value of 95%. 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. -