Our verdict is Uncertain significance. Variant got 2 ACMG points: 2P and 0B. PM2
The NM_007294.4(BRCA1):c.4083G>A(p.Met1361Ile) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000205 in 1,461,426 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 13/23 in silico tools predict a benign 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. M1361L) has been classified as 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]
Uncertain significance, criteria provided, single submitter
clinical testing
Ambry Genetics
Apr 06, 2023
The p.M1361I variant (also known as c.4083G>A), located in coding exon 9 of the BRCA1 gene, results from a G to A substitution at nucleotide position 4083. The methionine at codon 1361 is replaced by isoleucine, an amino acid with highly similar properties. This amino acid position is poorly conserved in available vertebrate species. In addition, this alteration is predicted to be tolerated by in silico analysis. 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
Nov 16, 2021
This missense variant replaces methionine with isoleucine at codon 1361 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). To our knowledge, functional studies have not been reported for this variant. This variant has not been reported in individuals affected with hereditary cancer in the literature. This variant has been identified in 1/250760 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 specified Uncertain:1
Uncertain significance, criteria provided, single submitter
clinical testing
Genetic Services Laboratory, University of Chicago
May 23, 2018
- -
Breast-ovarian cancer, familial, susceptibility to, 1 Uncertain:1
Uncertain significance, no assertion criteria provided
clinical testing
Sharing Clinical Reports Project (SCRP)
Mar 16, 2011
- -
not provided Uncertain:1
Uncertain significance, criteria provided, single submitter
clinical testing
GeneDx
Jun 08, 2016
This variant is denoted BRCA1 c.4083G>A at the cDNA level, p.Met1361Ile (M1361I) at the protein level, and results in the change of a Methionine to an Isoleucine (ATG>ATA). Using alternate nomenclature, this variant would be defined as BRCA1 4202G>A. This variant has been observed in at least one individual with ovarian cancer (Alsop 2012). BRCA1 Met1361Ile was not observed at a significant allele frequency in the NHLBI Exome Sequencing Project. Since Methionine and Isoleucine share similar properties, this is considered a conservative amino acid substitution. BRCA1 Met1361Ile occurs at a position that is not conserved and is located within the SCD domain and a region known to interact with multiple proteins (Narod 2004, Clark 2012, Paul 2014). In silico analyses predict that this variant is unlikely to alter protein structure or function. Based on currently available evidence, it is unclear whether BRCA1 Met1361Ile is a pathogenic or benign variant. We consider it to be a variant of uncertain significance. -
Malignant tumor of breast Uncertain:1
Uncertain significance, no assertion criteria provided
clinical testing
Department of Pathology and Laboratory Medicine, Sinai Health System
-
The p.Met1361Ile variant has not been previously reported in the literature nor by our laboratory. The p.Met1361 residue is not conserved in mammals and other species and in-silico or computational analyses (PolyPhen, SIFT and AlignGVGD) do not suggest a high likelihood of impact to the protein, but this information is not predictive enough to rule out pathogenicity. In summary, based on the current information presented above, this variant is classified as Variant of Unknown Significance (VUS). -
Hereditary breast ovarian cancer syndrome Uncertain:1
Uncertain significance, criteria provided, single submitter
clinical testing
Invitae
Jul 12, 2023
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: 37564). This variant has not been reported in the literature in individuals affected with BRCA1-related conditions. This variant is present in population databases (rs374192364, gnomAD no frequency). This sequence change replaces methionine, which is neutral and non-polar, with isoleucine, which is neutral and non-polar, at codon 1361 of the BRCA1 protein (p.Met1361Ile). 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. Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. -