Our verdict is Uncertain significance. Variant got 3 ACMG points: 4P and 1B. PM1PM5BP6
The ENST00000234420.11(MSH6):c.3259C>A(p.Pro1087Thr) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000421 in 1,614,002 control chromosomes in the GnomAD database, with no homozygous occurrence. 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. P1087A) has been classified as Likely benign.
MSH6 (HGNC:7329): (mutS homolog 6) This gene encodes a member of the DNA mismatch repair MutS family. In E. coli, the MutS protein helps in the recognition of mismatched nucleotides prior to their repair. A highly conserved region of approximately 150 aa, called the Walker-A adenine nucleotide binding motif, exists in MutS homologs. The encoded protein heterodimerizes with MSH2 to form a mismatch recognition complex that functions as a bidirectional molecular switch that exchanges ADP and ATP as DNA mismatches are bound and dissociated. Mutations in this gene may be associated with hereditary nonpolyposis colon cancer, colorectal cancer, and endometrial cancer. Transcripts variants encoding different isoforms have been described. [provided by RefSeq, Jul 2013]
FBXO11 (HGNC:13590): (F-box protein 11) This gene encodes a member of the F-box protein family which is characterized by an approximately 40 amino acid motif, the F-box. The F-box proteins constitute one of the four subunits of ubiquitin protein ligase complex called SCFs (SKP1-cullin-F-box), which function in phosphorylation-dependent ubiquitination. The F-box proteins are divided into 3 classes: Fbws containing WD-40 domains, Fbls containing leucine-rich repeats, and Fbxs containing either different protein-protein interaction modules or no recognizable motifs. The protein encoded by this gene belongs to the Fbxs class. It can function as an arginine methyltransferase that symmetrically dimethylates arginine residues, and it acts as an adaptor protein to mediate the neddylation of p53, which leads to the suppression of p53 function. This gene is known to be down-regulated in melanocytes from patients with vitiligo, a skin disorder that results in depigmentation. Polymorphisms in this gene are associated with chronic otitis media with effusion and recurrent otitis media (COME/ROM), a hearing loss disorder, and the knockout of the homologous mouse gene results in the deaf mouse mutant Jeff (Jf), a single gene model of otitis media. Alternatively spliced transcript variants encoding distinct isoforms have been identified for this gene. [provided by RefSeq, Jun 2010]
Verdict is Uncertain_significance. Variant got 3 ACMG points.
PM1
In a hotspot region, there are 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 7 benign, 17 uncertain in ENST00000234420.11
PM5
Other missense variant is known to change same aminoacid residue: Variant chr2-47803505-CCC-CT is described in Lovd as [Pathogenic].
BP6
Variant 2-47803506-C-A is Benign according to our data. Variant chr2-47803506-C-A is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 89359.We mark this variant Likely_benign, oryginal submissions are: {Benign=3, Uncertain_significance=2, Likely_benign=4}.
Uncertain significance, criteria provided, single submitter
curation
Sema4, Sema4
May 28, 2021
- -
Benign, criteria provided, single submitter
clinical testing
Color Diagnostics, LLC DBA Color Health
Feb 27, 2023
- -
Benign, criteria provided, single submitter
clinical testing
Ambry Genetics
May 07, 2021
This alteration is classified as benign based on a combination of the following: seen in unaffected individuals, population frequency, intact protein function, lack of segregation with disease, co-occurrence, RNA analysis, in silico models, amino acid conservation, lack of disease association in case-control studies, and/or the mechanism of disease or impacted region is inconsistent with a known cause of pathogenicity. -
Lynch syndrome 5 Uncertain:1Benign:1
Likely benign, criteria provided, single submitter
clinical testing
Myriad Genetics, Inc.
Nov 16, 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: 27363726]. -
Uncertain significance, criteria provided, single submitter
clinical testing
Illumina Laboratory Services, Illumina
Oct 13, 2017
This variant was observed as part of a predisposition screen in an ostensibly healthy population. A literature search was performed for the gene, cDNA change, and amino acid change (where applicable). Publications were found based on this search. However, the evidence from the literature, in combination with allele frequency data from public databases where available, was not sufficient to rule this variant in or out of causing disease. Therefore, this variant is classified as a variant of unknown significance. -
not provided Benign:2
Likely benign, criteria provided, single submitter
clinical testing
GeneDx
Nov 21, 2018
This variant is associated with the following publications: (PMID: 24040339, 12019211, 22102614, 17594722, 10537275, 15354210, 23621914, 11900875, 21120944, 26333163) -
Likely benign, criteria provided, single submitter
clinical testing
Quest Diagnostics Nichols Institute San Juan Capistrano
Mar 06, 2023
- -
MSH6-related disorder Uncertain:1
Uncertain significance, no assertion criteria provided
clinical testing
PreventionGenetics, part of Exact Sciences
Feb 09, 2024
The MSH6 c.3259C>A variant is predicted to result in the amino acid substitution p.Pro1087Thr. This variant was detected in an individual with a personal and family history of colorectal cancer (Kolodner et al. 1999. PubMed ID: 10537275). However, functional studies with recombinant MSH6 protein have indicated that dimerization with MSH2 and mismatch repair activity are not compromised by the p.Pro1087Thr variant (Kariola et al. 2002. PubMed ID: 12019211; Drost et al. 2012. PubMed ID: 22102614). This variant is documented in the gnomAD general population database with an allele frequency of ~0.04% among individuals of South Asian descent. In ClinVar, this variant has conflicting interpretations including likely benign and variant of uncertain significance (https://www.ncbi.nlm.nih.gov/clinvar/variation/89359/). However, at this time, the clinical significance of this variant is uncertain due to the absence of conclusive functional and genetic evidence. -
Ovarian cancer Benign:1
Benign, criteria provided, single submitter
clinical testing
Laboratory of Molecular Epidemiology of Birth Defects, West China Second University Hospital, Sichuan University