NM_000179.3:c.2926C>G

Variant names:

• chr2-47800909-C-G
• NM_000179.3:c.2926C>G

Variant summary

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

The NM_000179.3(MSH6):​c.2926C>G​(p.Arg976Gly) variant causes a missense change. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic 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, single submitter U:1
• Conservation: PhyloP100: 5.01

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, 0.958

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
MSH6	NM_000179.3	c.2926C>G	p.Arg976Gly	missense_variant	Exon 4 of 10	ENST00000234420.11	NP_000170.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
MSH6	ENST00000234420.11	c.2926C>G	p.Arg976Gly	missense_variant	Exon 4 of 10	1	NM_000179.3	ENSP00000234420.5

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 34

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Hereditary cancer-predisposing syndrome Uncertain:1

Mar 05, 2020

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The p.R976G variant (also known as c.2926C>G), located in coding exon 4 of the MSH6 gene, results from a C to G substitution at nucleotide position 2926. The arginine at codon 976 is replaced by glycine, an amino acid with dissimilar properties. A similar alteration at the same amino acid (c.2927G>A, p.R976H) has been reported in patients diagnosed with colorectal cancers demonstrating isolated loss/reduced staining of MSH6 on immunohistochemistry (Plaschke J et al. Int. J. Cancer, 2002 Feb;97:643-8; Salvador MU et al. J Clin Oncol. 2019 Mar 10;37(8):647-657). Additionally, functional studies have shown mismtach repair activity for p.R976H to be less than 50% of wild type (Cyr JL et al. J. Biol. Chem., 2008 Nov;283:31641-8; Drost M et al. Hum. Mutat., 2012 Mar;33:488-94). 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	0.98
BayesDel_addAF	Pathogenic	0.42	D
BayesDel_noAF	Pathogenic	0.36
CADD	Uncertain	25
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.75	.;.;D;T;.
Eigen	Pathogenic	0.82
Eigen_PC	Pathogenic	0.76
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Pathogenic	0.98	.;D;D;D;D
M_CAP	Uncertain	0.18	D
MetaRNN	Pathogenic	0.96	D;D;D;D;D
MetaSVM	Uncertain	0.55	D
MutationAssessor	Pathogenic	2.9	.;.;M;.;.
PrimateAI	Uncertain	0.57	T
PROVEAN	Pathogenic	-6.6	.;D;D;.;D
REVEL	Pathogenic	0.82
Sift	Pathogenic	0.0	.;D;D;.;D
Sift4G	Uncertain	0.0020	D;D;D;D;D
Polyphen		1.0	.;.;D;.;.
Vest4		0.85
MutPred		0.83		.;.;Loss of catalytic residue at R976 (P = 0.0396);.;.;
MVP		0.96
ClinPred		0.99	D
GERP RS		4.7
Varity_R		0.97
gMVP		0.90

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

No publications associated with this variant yet.

Other links and lift over

hg19: chr2-48028048;