Our verdict is Uncertain significance. Variant got 5 ACMG points: 5P and 0B. PM2PM5PP3
The NM_007294.4(BRCA1):c.4697C>A(p.Ser1566Tyr) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,856 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 Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. S1566?) has been classified as 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]
Uncertain significance, criteria provided, single submitter
clinical testing
Color Diagnostics, LLC DBA Color Health
Feb 27, 2023
This missense variant replaces serine with tyrosine at codon 1566 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). To our knowledge, functional studies have not been reported for this variant. This variant has not been reported in individuals affected with BRCA1-related disorders in the literature. This variant has not been identified 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. -
Uncertain significance, criteria provided, single submitter
clinical testing
Ambry Genetics
Oct 13, 2023
The p.S1566Y variant (also known as c.4697C>A), located in coding exon 14 of the BRCA1 gene, results from a C to A substitution at nucleotide position 4697. The serine at codon 1566 is replaced by tyrosine, an amino acid with dissimilar properties. 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:1
Uncertain significance, criteria provided, single submitter
clinical testing
Counsyl
Dec 07, 2017
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BRCA1-related disorder Uncertain:1
Uncertain significance, criteria provided, single submitter
clinical testing
PreventionGenetics, part of Exact Sciences
Aug 26, 2022
The BRCA1 c.4697C>A variant is predicted to result in the amino acid substitution p.Ser1566Tyr. To our knowledge, this variant has not been reported in the literature or in a large population database (http://gnomad.broadinstitute.org), indicating this variant is rare. At this time, the clinical significance of this variant is uncertain due to the absence of conclusive functional and genetic evidence. -
Hereditary breast ovarian cancer syndrome Uncertain:1
Uncertain significance, criteria provided, single submitter
clinical testing
Labcorp Genetics (formerly Invitae), Labcorp
Oct 27, 2024
This sequence change replaces serine, which is neutral and polar, with tyrosine, which is neutral and polar, at codon 1566 of the BRCA1 protein (p.Ser1566Tyr). 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: 409298). Invitae Evidence Modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) has been performed for this missense variant. However, the output from this modeling did not meet the statistical confidence thresholds required to predict the impact of this variant on BRCA1 protein function. 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. -
Familial cancer of breast Benign:1
Likely benign, criteria provided, single submitter
clinical testing
MGZ Medical Genetics Center
Feb 09, 2024
ACMG codes applied following ENIGMA VCEP rules: BP1_STR, PM2_SUP -