Our verdict is Uncertain significance. Variant got 0 ACMG points: 2P and 2B. PM2BP4_Moderate
The NM_007294.4(BRCA1):āc.4639T>Gā(p.Leu1547Val) 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 benign outcome for this variant. 13/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (ā ā ). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. L1547M) has been classified 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]
Verdict is Uncertain_significance. Variant got 0 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;
BP4
?
BP4 - Multiple lines of computational evidence suggest no impact on gene or gene product (conservation, evolutionary, splicing impact, etc.)
Computational evidence support a benign effect (MetaRNN=0.1567344).
Breast-ovarian cancer, familial, susceptibility to, 1 Uncertain:1
Uncertain significance, criteria provided, single submitter
clinical testing
Baylor Genetics
Aug 27, 2020
This variant was determined to be of uncertain significance according to ACMG Guidelines, 2015 [PMID:25741868]. -
not provided Uncertain:1
Uncertain significance, criteria provided, single submitter
clinical testing
Women's Health and Genetics/Laboratory Corporation of America, LabCorp
Apr 04, 2017
Variant summary: The BRCA1 c.4639T>G (p.Leu1547Val) variant causes a missense change involving the alteration of a non-conserved nucleotide. 4/4 in silico tools predict a benign outcome for this variant (SNPs&GO not captured due to low reliability index). Variant is not in any known functional domain of the protein (InterPro). This variant is absent in 121378 control chromosomes. The variant of interest has not, to our knowledge, been reported in affected individuals via publications and/or reputable databases/clinical diagnostic laboratories; nor evaluated for functional impact by in vivo/vitro studies. Because of the absence of clinical information and the lack of functional studies, the variant is classified as a variant of uncertain significance (VUS) until additional information becomes available. -
Uncertain significance, criteria provided, single submitter
clinical testing
Ambry Genetics
Mar 26, 2022
The p.L1547V variant (also known as c.4639T>G), located in coding exon 13 of the BRCA1 gene, results from a T to G substitution at nucleotide position 4639. The leucine at codon 1547 is replaced by valine, an amino acid with highly similar properties. This amino acid position is not well conserved in available vertebrate species. In addition, the in silico prediction for this alteration is inconclusive. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -
Hereditary breast ovarian cancer syndrome Uncertain:1
Uncertain significance, criteria provided, single submitter
clinical testing
Invitae
Jul 12, 2023
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. 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. ClinVar contains an entry for this variant (Variation ID: 496386). This variant has not been reported in the literature in individuals affected with BRCA1-related conditions. This variant is not present in population databases (gnomAD no frequency). This sequence change replaces leucine, which is neutral and non-polar, with valine, which is neutral and non-polar, at codon 1547 of the BRCA1 protein (p.Leu1547Val). -