Our verdict is Uncertain significance. Variant got 4 ACMG points: 5P and 1B. PM2PM5PP3BP6
The NM_007294.4(BRCA1):c.2590T>G(p.Ser864Ala) variant causes a missense 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 Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. S864L) 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 Uncertain_significance. Variant got 4 ACMG points.
PM2
?
PM2 - Absent from controls (or at extremely low frequency if recessive) in Exome Sequencing Project, 1000 Genomes Project, or Exome Aggregation Consortium
Very rare variant in population databases, with high coverage;
PM5
?
PM5 - Novel missense change at an amino acid residue where a different missense change determined to be pathogenic has been seen before
Other missense variant is known to change same aminoacid residue: Variant chr17-43092940-G-A is described in Lovd as [Pathogenic].
PP3
?
PP3 - Multiple lines of computational evidence support a deleterious effect on the gene or gene product (conservation, evolutionary, splicing impact, etc.)
MetaRNN computational evidence supports a deleterious effect, 0.814
BP6
?
BP6 - Reputable source recently reports variant as benign, but the evidence is not available to the laboratory to perform an independent evaluation
Variant 17-43092941-A-C is Benign according to our data. Variant chr17-43092941-A-C is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 54609.We mark this variant Likely_benign, oryginal submissions are: {Uncertain_significance=2, Likely_benign=1}.
Uncertain significance, criteria provided, single submitter
clinical testing
Ambry Genetics
Jul 29, 2014
The p.S864A variant (also known as c.2590T>G or 2709T>G), located in coding exon 9 of the BRCA1 gene, results from a T to G substitution at nucleotide position 2590. The serine at codon 864 is replaced by alanine, an amino acid with a few similar properties. This variant was previously reported in the SNPDatabase as rs80357285. This variant was not reported in population-based cohorts in the following databases: NHLBI Exome Sequencing Project (ESP) and 1000 Genomes Project. To date, this alteration has been detected with an allele frequency of approximately 0.002% (greater than 64000 alleles tested) in our clinical cohort. This amino acid position is highly conserved in available vertebrate species. In addition, this alteration is predicted to be probably damaging and deleterious by PolyPhen and SIFT in silico analyses, respectively. Since supporting evidence is limited at this time, the clinical significance of p.S864A remains unclear. -
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). -
Breast-ovarian cancer, familial, susceptibility to, 1 Uncertain:1
Uncertain significance, no assertion criteria provided
clinical testing
Breast Cancer Information Core (BIC) (BRCA1)
Nov 25, 2004
- -
Hereditary breast ovarian cancer syndrome Uncertain:1
Uncertain significance, criteria provided, single submitter
clinical testing
Invitae
Aug 24, 2016
In summary, this variant is a novel missense change with uncertain impact on protein function. It has been classified as a Variant of Uncertain Significance. Algorithms developed to predict the effect of missense changes on protein structure and function do not agree on the potential impact of this missense change (SIFT: "Tolerated"; PolyPhen-2: "Probably Damaging"; Align-GVGD: "Class C0"). This variant is not present in population databases (ExAC no frequency) and has not been reported in the literature in individuals with a BRCA1-related disease. ClinVar contains an entry for this variant (Variation ID: 54609). This sequence change replaces serine with alanine at codon 864 of the BRCA1 protein (p.Ser864Ala). The serine residue is highly conserved and there is a moderate physicochemical difference between serine and alanine. -