rs1553414327

chr2-47800939-A-G

Variant summary

Our verdict is Likely benign. Variant got -4 ACMG points: 0P and 4B. BP4_Strong

The NM_000179.3(MSH6):c.2956A>G(p.Thr986Ala) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000773 in 1,423,344 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 16/20 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. T986S) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000077 (0 hom.)
• Consequence: MSH6 NM_000179.3 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:5 O:1
• Conservation: PhyloP100: 0.197

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_benign. Variant got -4 ACMG points.

• BP4: Computational evidence support a benign effect (MetaRNN=0.048820615).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
MSH6	NM_000179.3	c.2956A>G	p.Thr986Ala	missense_variant	4/10	ENST00000234420.11

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
MSH6	ENST00000234420.11	c.2956A>G	p.Thr986Ala	missense_variant	4/10	1	NM_000179.3	P4

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000773 AC: 11 AN: 1423344 Hom.: 0 Cov.: 34 AF XY: 0.00000710 AC XY: 5 AN XY: 704352

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: 0.0000125

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000914

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:5 Other:1

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Hereditary cancer-predisposing syndrome Uncertain:2

Uncertain significance, criteria provided, single submitter	clinical testing	Color Diagnostics, LLC DBA Color Health	May 10, 2021	This missense variant replaces threonine with alanine at codon 986 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). 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 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. -
Uncertain significance, criteria provided, single submitter	clinical testing	Ambry Genetics	Jul 23, 2021	The p.T986A variant (also known as c.2956A>G), located in coding exon 4 of the MSH6 gene, results from an A to G substitution at nucleotide position 2956. The threonine at codon 986 is replaced by alanine, an amino acid with similar properties. This amino acid position is poorly conserved in available vertebrate species. In addition, this alteration is predicted to be tolerated by in silico analysis. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -

not provided Uncertain:1 Other:1

not provided, no classification provided	phenotyping only	GenomeConnect, ClinGen	-	Variant interpreted as Uncertain significance and reported on 06-13-2019 by Lab or GTR ID 26957. 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. -
Uncertain significance, criteria provided, single submitter	clinical testing	GeneDx	Jun 28, 2019	Not observed in large population cohorts (Lek et al., 2016); In silico analysis, which includes protein predictors and evolutionary conservation, supports that this variant does not alter protein structure/function; Has not been previously published as pathogenic or benign to our knowledge -

not specified Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

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

Nov 05, 2018

Variant summary: MSH6 c.2956A>G (p.Thr986Ala) results in a non-conservative amino acid change located in the DNA mismatch repair protein MutS, Clamp domain (IPR007696) of the encoded protein sequence. Four of five in-silico tools predict a benign effect of the variant on protein function. The variant was absent in 246084 control chromosomes (gnomAD). The available data on variant occurrences in the general population are insufficient to allow any conclusion about variant significance. To our knowledge, no occurrence of c.2956A>G in individuals affected with Lynch Syndrome and no experimental evidence demonstrating its impact on protein function have been reported. Two clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014 without evidence for independent evaluation, and both laboratories classified the variant as uncertain significance. Based on the evidence outlined above, the variant was classified as uncertain significance. -

Hereditary nonpolyposis colorectal neoplasms Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Sep 11, 2023

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. ClinVar contains an entry for this variant (Variation ID: 485854). 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). This sequence change replaces threonine, which is neutral and polar, with alanine, which is neutral and non-polar, at codon 986 of the MSH6 protein (p.Thr986Ala). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.061
BayesDel_addAF	Benign	-0.17	T
BayesDel_noAF	Benign	-0.49
Cadd	Benign	8.3
Dann	Benign	0.72
Eigen	Benign	-0.88
Eigen_PC	Benign	-0.75
FATHMM_MKL	Benign	0.35	N
M_CAP	Benign	0.047	D
MetaRNN	Benign	0.049	T;T;T;T;T
MetaSVM	Benign	-0.80	T
MutationTaster	Benign	1.0	N;N;N;N
PrimateAI	Benign	0.33	T
Sift4G	Benign	1.0	T;T;T;T;T
Polyphen		0.0	.;.;B;.;.
Vest4		0.074
MutPred		0.39		.;.;Loss of phosphorylation at T986 (P = 0.0691);.;.;
MVP		0.64
ClinPred		0.020	T
GERP RS		2.0
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.11
gMVP		0.28

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: rs1553414327; hg19: chr2-48028078;