rs761643896

Positions:

• chr2-47806324-A-C
• chr2-47806324-A-G
• chr2-47806324-A-T

Variant summary

Our verdict is Likely benign. Variant got -2 ACMG points: 0P and 2B. BP4_Moderate

The NM_000179.3(MSH6):​c.3767A>C​(p.Tyr1256Ser) variant causes a missense change. The variant allele was found at a frequency of 0.0000041 in 1,461,838 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 Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. Y1256N) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0000041 (0 hom.)
• Consequence: MSH6 NM_000179.3 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:6
• Conservation: PhyloP100: 5.55

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 -2 ACMG points.

• BP4: Computational evidence support a benign effect (MetaRNN=0.25783202).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
MSH6	NM_000179.3	c.3767A>C	p.Tyr1256Ser	missense_variant	8/10	ENST00000234420.11

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
MSH6	ENST00000234420.11	c.3767A>C	p.Tyr1256Ser	missense_variant	8/10	1	NM_000179.3	P4

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD3 exomes AF: 0.00000796 AC: 2 AN: 251224 Hom.: 0 AF XY: 0.00 AC XY: 0 AN XY: 135776

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.0000579

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.00

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: 1461838 Hom.: 0 Cov.: 33 AF XY: 0.00000138 AC XY: 1 AN XY: 727216

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.0000447

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000360

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 33

ExAC AF: 0.00000824 AC: 1

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:6

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not provided Uncertain:2

Uncertain significance, criteria provided, single submitter	clinical testing	Quest Diagnostics Nichols Institute San Juan Capistrano	Oct 04, 2019	- -
Uncertain significance, criteria provided, single submitter	clinical testing	GeneDx	Mar 17, 2023	Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; Has not been previously published as pathogenic or benign to our knowledge; This variant is associated with the following publications: (PMID: 32686686, 17531815, 21120944) -

Hereditary cancer-predisposing syndrome Uncertain:2

Uncertain significance, criteria provided, single submitter	clinical testing	Ambry Genetics	Apr 11, 2023	The p.Y1256S variant (also known as c.3767A>C), located in coding exon 8 of the MSH6 gene, results from an A to C substitution at nucleotide position 3767. The tyrosine at codon 1256 is replaced by serine, an amino acid with dissimilar properties. This amino acid position is well 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. -
Uncertain significance, criteria provided, single submitter	clinical testing	Color Diagnostics, LLC DBA Color Health	Sep 14, 2023	This missense variant replaces tyrosine with serine at codon 1256 of the MSH6 protein. Computational prediction tool 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 MSH6-related disorders in the literature. This variant has been identified in 2/251224 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

Oct 06, 2023

This missense variant replaces tyrosine with serine at codon 1256 of the MSH6 protein. Computational prediction tool 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). 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 2/251224 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. -

Hereditary nonpolyposis colorectal neoplasms Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Sep 19, 2022

This sequence change replaces tyrosine, which is neutral and polar, with serine, which is neutral and polar, at codon 1256 of the MSH6 protein (p.Tyr1256Ser). This variant is present in population databases (rs761643896, gnomAD 0.006%). 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: 428336). 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) has been performed at Invitae for this missense variant, however the output from this modeling did not meet the statistical confidence thresholds required to predict the impact of this variant on MSH6 protein function. 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. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.34
BayesDel_addAF	Pathogenic	0.29	D
BayesDel_noAF	Pathogenic	0.17
CADD	Uncertain	25
DANN	Uncertain	0.99
DEOGEN2	Benign	0.092	T
Eigen	Uncertain	0.25
Eigen_PC	Uncertain	0.40
FATHMM_MKL	Uncertain	0.95	D
LIST_S2	Benign	0.25	T
M_CAP	Benign	0.034	D
MetaRNN	Benign	0.26	T
MetaSVM	Uncertain	0.12	D
MutationTaster	Benign	1.0	D;D;D;D
Sift4G	Benign	0.71	T
Vest4		0.46
MVP		0.90
ClinPred		0.97	D
GERP RS		5.5

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: rs761643896; hg19: chr2-48033463;