2-47798966-G-T

Variant names:

• chr2-47798966-G-T
• rs1060502879
• NM_000179.3:c.983G>T

Variant summary

Our verdict is Uncertain significance. The variant received 0 ACMG points: 2P and 2B. PM2 BP4_Moderate

The NM_000179.3(MSH6):​c.983G>T​(p.Ser328Ile) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign outcome for this variant. 16/22 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. S328G) has been classified as Likely benign.

• Frequency: Genomes: not found (cov: 32)
• Consequence: MSH6 NM_000179.3 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:3
• Conservation: PhyloP100: 1.42
• Publications: 1 publications found

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]

FBXO11 Gene-Disease associations (from GenCC):

• intellectual developmental disorder with dysmorphic facies and behavioral abnormalities

  Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), Ambry Genetics, G2P

ACMG classification

Our verdict: Uncertain_significance. The variant received 0 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.10407135).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
MSH6	NM_000179.3	c.983G>T	p.Ser328Ile	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.983G>T	p.Ser328Ile	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:3

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Hereditary cancer-predisposing syndrome Uncertain:2

Dec 29, 2015

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The p.S328I variant (also known as c.983G>T), located in coding exon 4 of the MSH6 gene, results from a G to T substitution at nucleotide position 983. The serine at codon 328 is replaced by isoleucine, an amino acid with dissimilar properties. This variant was not reported in population based cohorts in the following databases: Database of Single Nucleotide Polymorphisms (dbSNP), NHLBI Exome Sequencing Project (ESP), and 1000 Genomes Project. In the ESP, this variant was not observed in 6503 samples (13006 alleles) with coverage at this position. To date, this alteration has been detected with an allele frequency of approximately 0.001% (greater than 115000 alleles tested) in our clinical cohort. This amino acid position is poorly conserved in available vertebrate species. In addition, this alteration is predicted to be tolerated by in silico analysis. In addition, the CoDP in silico tool predicts this alteration to have a minor impact on molecular function, with a score of 0.000 (Terui H et al. J Biomed Sci. 2013;20:25). Since supporting evidence is limited at this time, the clinical significance of p.S328I remains unclear. -

Sep 19, 2019

Color Diagnostics, LLC DBA Color Health

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This missense variant replaces serine with isoleucine at codon 328 of the MSH6 protein. Computational prediction tool 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 not been identified 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. -

Hereditary nonpolyposis colorectal neoplasms Uncertain:1

Sep 12, 2021

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

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 not expected to disrupt MSH6 protein function. This sequence change replaces serine with isoleucine at codon 328 of the MSH6 protein (p.Ser328Ile). The serine residue is weakly conserved and there is a large physicochemical difference between serine and isoleucine. This variant is not present in population databases (ExAC no frequency). This variant has not been reported in the literature in individuals affected with MSH6-related conditions. ClinVar contains an entry for this variant (Variation ID: 921522). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.088
BayesDel_addAF	Benign	-0.079	T
BayesDel_noAF	Benign	-0.35
CADD	Benign	18
DANN	Benign	0.96
DEOGEN2	Uncertain	0.75	.;.;D;T;.
Eigen	Benign	-0.66
Eigen_PC	Benign	-0.63
FATHMM_MKL	Benign	0.32	N
LIST_S2	Benign	0.65	.;T;T;T;T
M_CAP	Benign	0.055	D
MetaRNN	Benign	0.10	T;T;T;T;T
MetaSVM	Benign	-0.70	T
MutationAssessor	Benign	0.90	.;.;L;.;.
PhyloP100		1.4
PrimateAI	Benign	0.26	T
PROVEAN	Uncertain	-2.4	.;N;D;.;N
REVEL	Benign	0.065
Sift	Benign	0.15	.;T;T;.;T
Sift4G	Benign	0.15	T;T;T;T;T
Polyphen		0.012	.;.;B;.;.
Vest4		0.16
MutPred		0.28		.;.;Loss of phosphorylation at S328 (P = 0.0211);.;.;
MVP		0.78
ClinPred		0.068	T
GERP RS		2.5
Varity_R		0.084
gMVP		0.24
Mutation Taster		=91/9	polymorphism

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

Other links and lift over

dbSNP: rs1060502879; hg19: chr2-48026105;