2-47799463-G-T

Variant names:

• chr2-47799463-G-T
• rs758699749
• NM_000179.3:c.1480G>T

Variant summary

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

The NM_000179.3(MSH6):​c.1480G>T​(p.Ala494Ser) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000041 in 1,461,864 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000041 (0 hom.)
• Consequence: MSH6 NM_000179.3 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:3 B:1 O:1
• Conservation: PhyloP100: 8.13

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.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
MSH6	NM_000179.3	c.1480G>T	p.Ala494Ser	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.1480G>T	p.Ala494Ser	missense_variant	Exon 4 of 10	1	NM_000179.3	ENSP00000234420.5

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD3 exomes AF: 0.00000398 AC: 1 AN: 251208 Hom.: 0 AF XY: 0.00 AC XY: 0 AN XY: 135754

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: 0.00000410 AC: 6 AN: 1461864 Hom.: 0 Cov.: 34 AF XY: 0.00000275 AC XY: 2 AN XY: 727226

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: 0.0000696

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ExAC AF: 0.00000824 AC: 1

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:3 Benign:1 Other:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Hereditary cancer-predisposing syndrome Uncertain:2

Apr 19, 2023

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The p.A494S variant (also known as c.1480G>T), located in coding exon 4 of the MSH6 gene, results from a G to T substitution at nucleotide position 1480. The alanine at codon 494 is replaced by serine, an amino acid with similar properties. This amino acid position is highly 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. -

Nov 18, 2021

Color Diagnostics, LLC DBA Color Health

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This missense variant replaces alanine with serine at codon 494 of the MSH6 protein. Computational prediction is inconclusive regarding the impact of this variant on protein structure and function (internally defined REVEL score threshold 0.5 < inconclusive < 0.7, 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 1/251208 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 5 Uncertain:1

-

Neuberg Centre For Genomic Medicine, NCGM

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The missense c.1480G>T (p.Ala494Ser) variant in MSH6 gene has not been reported previously as a pathogenic variant nor as a benign variant, to our knowledge. The p.Ala494Ser variant has allele frequency 0.0004% in gnomAD Exomes and is novel (not in any individuals) in 1000 Genomes. This variant has been reported to the ClinVar database as Likely benign / Uncertain Significance. The amino acid change p.Ala494Ser in MSH6 is predicted as conserved by GERP++ and PhyloP across 100 vertebrates. The p.Ala494Ser variant is novel (not in any individuals) in 1000 Genomes. The amino acid Ala at position 494 is changed to a Ser changing protein sequence and it might alter its composition and physico-chemical properties. For these reasons, this variant has been classified as Variant of Uncertain Significance (VUS). -

Hereditary nonpolyposis colorectal neoplasms Benign:1

Oct 30, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Lynch syndrome Other:1

-

GenomeConnect, ClinGen

Significance: not provided

Review Status: no classification provided

Collection Method: phenotyping only

Variant classified as Uncertain significance and reported on 05-21-2019 by Lab or GTR ID 506138. GenomeConnect assertions are reported exactly as they appear on the patient-provided report from the testing laboratory. GenomeConnect staff make no attempt to reinterpret the clinical significance of the variant. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.094
BayesDel_addAF	Uncertain	0.14	D
BayesDel_noAF	Uncertain	0.060
CADD	Benign	23
DANN	Uncertain	0.99
DEOGEN2	Benign	0.37	.;.;T;T;.
Eigen	Uncertain	0.29
Eigen_PC	Uncertain	0.43
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.88	.;D;D;D;D
M_CAP	Uncertain	0.11	D
MetaRNN	Uncertain	0.45	T;T;T;T;T
MetaSVM	Uncertain	0.24	D
MutationAssessor	Benign	1.6	.;.;L;.;.
PrimateAI	Uncertain	0.59	T
PROVEAN	Benign	-0.43	.;N;N;.;N
REVEL	Uncertain	0.51
Sift	Benign	0.095	.;T;T;.;T
Sift4G	Benign	0.16	T;T;T;T;T
Polyphen		0.42	.;.;B;.;.
Vest4		0.54
MutPred		0.43		.;.;Gain of phosphorylation at A494 (P = 0.0207);.;.;
MVP		0.82
ClinPred		0.62	D
GERP RS		5.3
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.29
gMVP		0.33

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: rs758699749; hg19: chr2-48026602;