Our verdict is Pathogenic. Variant got 16 ACMG points: 16P and 0B. PM1PM2PM5PP3_ModeratePP5_Very_Strong
The NM_007294.4(BRCA1):āc.110C>Gā(p.Thr37Arg) variant causes a missense change. The variant allele was found at a frequency of 0.00000124 in 1,613,576 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 Likely pathogenic (ā ā ). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. T37K) 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]
Verdict is Pathogenic. Variant got 16 ACMG points.
PM1
In a zinc_finger_region RING-type (size 41) in uniprot entity BRCA1_HUMAN there are 65 pathogenic changes around while only 6 benign (92%) in NM_007294.4
PM2
Very rare variant in population databases, with high coverage;
PM5
Other missense variant is known to change same aminoacid residue: Variant chr17-43115750-G-T is described in Lovd as [Pathogenic].
PP3
MetaRNN computational evidence supports a deleterious effect, 0.874
PP5
Variant 17-43115750-G-C is Pathogenic according to our data. Variant chr17-43115750-G-C is described in ClinVar as [Likely_pathogenic]. Clinvar id is 54132.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
The p.T37R pathogenic mutation (also known as c.110C>G), located in coding exon 2 of the BRCA1 gene, results from a C to G substitution at nucleotide position 110. The threonine at codon 37 is replaced by arginine, an amino acid with similar properties. This alteration has been identified in one woman belonging to an early onset breast cancer cohort (Haffty BG et al. J. Med. Genet. 2006 Feb; 43(2):133-7). Several independent DNA repair assays showed loss of function in p.T37R mutants for BRCA1 ubiquitin ligase activity, heterochromatin-mediated silencing, homology directed recombination, and single strand annealing (Morris JR et al. Hum Mol Genet. 2006; 15:599-606; Ransburgh DJ et al. Cancer Res. 2010; 70:988-95; Towler WI et al. Hum Mutat. 2013; Ruffner H et al. Proc. Natl. Acad. Sci. U.S.A. 2001 Apr; 98(9):5134-9; Zhu Q et al. Nature 2011 Sep; 477(7363):179-84). Another functional study found that this nucleotide substitution is non-functional in a high-throughput, genome editing, haploid cell survival assay (Findlay GM et al. Nature. 2018 10;562:217-222). Based on internal structural analysis, this variant is anticipated to result in a significant decrease in structural stability (Brzovic PS et al. Nat. Struct. Biol. 2001 Oct;8(10):833-7; Ambry Internal Data). This variant is considered to be rare based on population cohorts in the Genome Aggregation Database (gnomAD). This amino acid position is highly conserved in available vertebrate species. In addition, this alteration is predicted to be deleterious by in silico analysis. Based on the supporting evidence, this alteration is interpreted as a disease-causing mutation. -
Likely pathogenic, criteria provided, single submitter
curation
Sema4, Sema4
Nov 15, 2021
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Hereditary breast ovarian cancer syndrome Pathogenic:1
Pathogenic, criteria provided, single submitter
clinical testing
Labcorp Genetics (formerly Invitae), Labcorp
Oct 08, 2023
This sequence change replaces threonine, which is neutral and polar, with arginine, which is basic and polar, at codon 37 of the BRCA1 protein (p.Thr37Arg). This variant is not present in population databases (gnomAD no frequency). This missense change has been observed in individual(s) with breast cancer (PMID: 15983021, 19491284). ClinVar contains an entry for this variant (Variation ID: 54132). Advanced modeling performed at Invitae incorporating data from internal and/or published experimental studies (PMID: 30209399) indicates that this missense variant is expected to disrupt BRCA1 function. Experimental studies have shown that this missense change affects BRCA1 function (PMID: 11320250, 19543972, 20103620, 30209399). This variant disrupts the p.Thr37 amino acid residue in BRCA1. Other variant(s) that disrupt this residue have been determined to be pathogenic (PMID: 19543972, 21990134, 25823446, 27272900, 28664506, 30209399). This suggests that this residue is clinically significant, and that variants that disrupt this residue are likely to be disease-causing. For these reasons, this variant has been classified as Pathogenic. -