Our verdict is Uncertain significance. Variant got 0 ACMG points: 2P and 2B. PM2BP4BP6
The ENST00000357654.9(BRCA1):c.3377C>T(p.Pro1126Leu) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000274 in 1,460,950 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 12/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Synonymous variant affecting the same amino acid position (i.e. P1126P) 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 0 ACMG points.
PM2
Very rare variant in population databases, with high coverage;
BP4
Computational evidence support a benign effect (MetaRNN=0.33352435).
BP6
Variant 17-43092154-G-A is Benign according to our data. Variant chr17-43092154-G-A is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 54862.We mark this variant Likely_benign, oryginal submissions are: {Uncertain_significance=4, Likely_benign=2}.
Breast-ovarian cancer, familial, susceptibility to, 1 Uncertain:2Benign:1
Uncertain significance, no assertion criteria provided
clinical testing
Breast Cancer Information Core (BIC) (BRCA1)
Dec 23, 2003
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Uncertain significance, no assertion criteria provided
clinical testing
BRCAlab, Lund University
Mar 02, 2020
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Likely benign, criteria provided, single submitter
clinical testing
Myriad Genetics, Inc.
May 05, 2023
This variant is considered likely benign. This variant is strongly associated with less severe personal and family histories of cancer, typical for individuals without pathogenic variants in this gene [PMID: 25085752]. -
Uncertain significance, criteria provided, single submitter
clinical testing
Ambry Genetics
Dec 22, 2023
The p.P1126L variant (also known as c.3377C>T), located in coding exon 9 of the BRCA1 gene, results from a C to T substitution at nucleotide position 3377. The proline at codon 1126 is replaced by leucine, an amino acid with very few similar properties. A study of 1477 BRCA1 alterations classified the p.P1126L variant as 'uncertain clinical significance' (Judkins T et al. Cancer Res. 2005 Nov;65:10096-103). 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. -
Uncertain significance, criteria provided, single submitter
clinical testing
Color Diagnostics, LLC DBA Color Health
Oct 22, 2019
This missense variant replaces proline with leucine at codon 1126 of the BRCA1 protein. Computational prediction suggests that this variant may not impact protein structure and function (internally defined REVEL score threshold <= 0.5, PMID: 27666373). Splice site prediction tools suggest that this variant may not impact RNA splicing. To our knowledge, functional studies have not been performed for this variant. This variant has not been reported in individuals affected with hereditary cancer in the literature. This variant has been identified in 2/250460 chromosomes 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. -
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). -
not provided Uncertain:1
Uncertain significance, criteria provided, single submitter
clinical testing
GeneDx
Jan 17, 2024
Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; Also known as 3496C>T; This variant is associated with the following publications: (PMID: 15385441, 29884841, 32377563, 31911673, 31853058, 34981296, 16267036) -
Hereditary breast ovarian cancer syndrome Uncertain:1
Uncertain significance, criteria provided, single submitter
clinical testing
Labcorp Genetics (formerly Invitae), Labcorp
Mar 18, 2022
This sequence change replaces proline, which is neutral and non-polar, with leucine, which is neutral and non-polar, at codon 1126 of the BRCA1 protein (p.Pro1126Leu). This variant is present in population databases (rs80356887, gnomAD 0.002%). 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: 54862). 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. 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. -