chr2-47798800-G-A

Position:

• chr2-47798800-G-A

Variant summary

Our verdict is Uncertain significance. Variant got 0 ACMG points: 2P and 2B. PM2 BP4_Moderate

The ENST00000234420.11(MSH6):​c.817G>A​(p.Gly273Arg) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000137 in 1,461,886 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts 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. G273V) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: MSH6 ENST00000234420.11 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:4 B:1
• Conservation: PhyloP100: 9.03

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 Uncertain_significance. Variant got 0 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.25121015).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
MSH6	NM_000179.3	c.817G>A	p.Gly273Arg	missense_variant	4/10	ENST00000234420.11	NP_000170.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
MSH6	ENST00000234420.11	c.817G>A	p.Gly273Arg	missense_variant	4/10	1	NM_000179.3	ENSP00000234420	P4

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD3 exomes AF: 0.00000398 AC: 1 AN: 251074 Hom.: 0 AF XY: 0.00000737 AC XY: 1 AN XY: 135680

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.0000327

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000137 AC: 2 AN: 1461886 Hom.: 0 Cov.: 34 AF XY: 0.00000138 AC XY: 1 AN XY: 727240

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.0000116

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00

Gnomad4 OTH exome AF: 0.0000166

GnomAD4 genome Cov.: 32

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:4 Benign:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Hereditary cancer-predisposing syndrome Uncertain:2

Uncertain significance, criteria provided, single submitter	clinical testing	Ambry Genetics	Jun 03, 2022	The p.G273R variant (also known as c.817G>A), located in coding exon 4 of the MSH6 gene, results from a G to A substitution at nucleotide position 817. The glycine at codon 273 is replaced by arginine, an amino acid with dissimilar properties. This amino acid position is not well conserved in available vertebrate species. In addition, the in silico prediction for this alteration is inconclusive. 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	Jan 02, 2020	This missense variant replaces glycine with arginine at codon 273 of the MSH6 protein. Computational prediction suggests that this variant may not impact protein structure and function (internally defined REVEL score threshold <= 0.5, PMID: 27666373). Splice site prediction tools suggest that this variant may not impact RNA splicing. To our knowledge, functional studies have not been performed for this variant. This variant has not been reported in individuals affected with hereditary cancer in the literature. This variant has been identified in 1/251074 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. -

Lynch syndrome Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

All of Us Research Program, National Institutes of Health

Jan 11, 2024

This missense variant replaces glycine with arginine at codon 273 of the MSH6 protein. Computational prediction suggests that this variant may not impact protein structure and function (internally defined REVEL score threshold <= 0.5, PMID: 27666373). Splice site prediction tools suggest that this variant may not impact RNA splicing. To our knowledge, functional studies have not been performed for this variant. This variant has not been reported in individuals affected with hereditary cancer in the literature. This variant has been identified in 1/251074 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. -

not provided Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

GeneDx

Jul 20, 2017

This variant is denoted MSH6 c.817G>A at the cDNA level, p.Gly273Arg (G273R) at the protein level, and results in the change of a Glycine to an Arginine (GGA>AGA). This variant has not, to our knowledge, been published in the literature as pathogenic or benign. MSH6 Gly273Arg was not observed in large population cohorts (NHLBI Exome Sequencing Project, The 1000 Genomes Consortium 2015, Lek 2016). Since Glycine and Arginine differ in polarity, charge, size or other properties, this is considered a non-conservative amino acid substitution. MSH6 Gly273Arg occurs at a position where amino acids with properties similar to Glycine are tolerated across species and is located in the nuclear localization signals (Gassman 2011). In silico analyses are inconsistent regarding the effect this variant may have on protein structure and function. Based on currently available evidence, it is unclear whether MSH6 Gly273Arg is a pathogenic or benign variant. We consider it to be a variant of uncertain significance. -

Hereditary nonpolyposis colorectal neoplasms Benign:1

Likely benign, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Aug 28, 2023

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.20
BayesDel_addAF	Uncertain	0.057	T
BayesDel_noAF	Uncertain	-0.060
CADD	Uncertain	24
DANN	Uncertain	1.0
DEOGEN2	Benign	0.32	.;T;T
Eigen	Uncertain	0.35
Eigen_PC	Uncertain	0.42
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Uncertain	0.93	D;D;D
M_CAP	Uncertain	0.16	D
MetaRNN	Benign	0.25	T;T;T
MetaSVM	Uncertain	0.069	D
MutationAssessor	Benign	1.9	.;M;.
MutationTaster	Benign	1.0	D;D;D;D
PrimateAI	Benign	0.45	T
PROVEAN	Benign	-1.2	N;N;.
REVEL	Uncertain	0.39
Sift	Uncertain	0.016	D;D;.
Sift4G	Benign	0.11	T;T;T
Polyphen		0.18	.;B;.
Vest4		0.25
MutPred		0.12		.;Gain of solvent accessibility (P = 0.1319);.;
MVP		0.88
ClinPred		0.65	D
GERP RS		4.3
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.19
gMVP		0.063

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: rs587779948; hg19: chr2-48025939; COSMIC: COSV52277404; COSMIC: COSV52277404;