2-47790986-C-T

Variant names:

• chr2-47790986-C-T
• rs878853732
• NM_000179.3:c.320C>T

Variant summary

Our verdict is Likely pathogenic. Variant got 6 ACMG points: 6P and 0B. PM2 PP3_Strong

The NM_000179.3(MSH6):​c.320C>T​(p.Pro107Leu) variant causes a missense change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. 12/20 in silico tools predict a damaging outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★).

• Frequency: Genomes: not found (cov: 32)
• Consequence: MSH6 NM_000179.3 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:4
• Conservation: PhyloP100: 7.91

Genes affected

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]

ACMG classification

Verdict is Likely_pathogenic. Variant got 6 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.973

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
MSH6	NM_000179.3	c.320C>T	p.Pro107Leu	missense_variant	Exon 2 of 10	ENST00000234420.11	NP_000170.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
MSH6	ENST00000234420.11	c.320C>T	p.Pro107Leu	missense_variant	Exon 2 of 10	1	NM_000179.3	ENSP00000234420.5

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 33

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:4

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not provided Uncertain:2

Feb 16, 2017

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Variant summary: The MSH6 c.320C>T (p.Pro107Leu) variant located in the PWWP domain (via InterPro) involves the alteration of a conserved nucleotide, which 4/4 in silico tools (SNPs&GO not captured due to low reliability index) predict a damaging outcome, although these predictions have yet to be functionally assessed. The variant of interest has not been observed in controls (ExAC, 1000 Gs, or ESP), nor has it been, to our knowledge, reported in affected individuals via publications. A clinical diagnostic laboratory reports the variant with a classification of "uncertain significance." Therefore, until additional information becomes available (ie, clinical and functional studies), the variant of interest has been classified as a "Variant of Uncertain Significance." -

Jul 24, 2023

Quest Diagnostics Nichols Institute San Juan Capistrano

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant has not been reported as a germline variant in individuals with MSH6-related conditions in the published literature. It also has not been reported in large, multi-ethnic general populations (Genome Aggregation Database, http://gnomad.broadinstitute.org). Analysis of this variant using bioinformatics tools for the prediction of the effect of amino acid changes on protein structure and function yielded predictions that this variant is damaging. Based on the available information, we are unable to determine the clinical significance of this variant. -

Hereditary nonpolyposis colorectal neoplasms Uncertain:1

Nov 11, 2021

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces proline, which is neutral and non-polar, with leucine, which is neutral and non-polar, at codon 107 of the MSH6 protein (p.Pro107Leu). 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 expected to disrupt MSH6 protein function. ClinVar contains an entry for this variant (Variation ID: 237183). This variant has not been reported in the literature in individuals affected with MSH6-related conditions. This variant is not present in population databases (gnomAD no frequency). -

Hereditary cancer-predisposing syndrome Uncertain:1

Feb 13, 2024

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The p.P107L variant (also known as c.320C>T), located in coding exon 2 of the MSH6 gene, results from a C to T substitution at nucleotide position 320. The proline at codon 107 is replaced by leucine, an amino acid with similar properties. This amino acid position is highly conserved in available vertebrate species. In addition, this alteration is predicted to be deleterious by in silico analysis. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.96
BayesDel_addAF	Pathogenic	0.51	D
BayesDel_noAF	Pathogenic	0.49
CADD	Pathogenic	28
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.76	.;D;T;.;D;D
Eigen	Pathogenic	1.1
Eigen_PC	Pathogenic	0.98
FATHMM_MKL	Uncertain	0.96	D
LIST_S2	Pathogenic	0.98	.;D;D;D;D;D
M_CAP	Pathogenic	0.58	D
MetaRNN	Pathogenic	0.97	D;D;D;D;D;D
MetaSVM	Pathogenic	0.99	D
MutationAssessor	Pathogenic	3.7	.;H;.;.;.;.
PrimateAI	Pathogenic	0.81	D
PROVEAN	Uncertain	-4.2	.;D;.;D;D;D
REVEL	Pathogenic	0.93
Sift	Pathogenic	0.0	.;D;.;D;D;D
Sift4G	Pathogenic	0.0	D;D;D;D;D;D
Polyphen		1.0	.;D;.;.;.;.
Vest4		0.83, 0.92
MutPred		0.88		.;Gain of sheet (P = 0.0477);.;.;.;.;
MVP		0.99
ClinPred		1.0	D
GERP RS		5.8
Varity_R		0.98
gMVP		0.94

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.0		Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

LitVar

Other links and lift over

dbSNP: rs878853732; hg19: chr2-48018125;