NM_000179.3:c.733A>T

Variant names:

• chr2-47798716-A-T
• rs762168786
• NM_000179.3:c.733A>T

Variant summary

Our verdict is Likely benign. The variant received -5 ACMG points: 0P and 5B. BP4_Strong BS1_Supporting

The NM_000179.3(MSH6):​c.733A>T​(p.Ile245Leu) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000155 in 1,614,080 control chromosomes in the GnomAD database, including 1 homozygotes. In-silico tool predicts a benign outcome for this variant. 17/22 in silico tools predict 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. I245V) has been classified as Likely benign.

• Frequency:
  • Genomes: 𝑓 0.000020 (0 hom., cov: 32)
  • Exomes 𝑓: 0.000015 (1 hom.)
• Consequence: MSH6 NM_000179.3 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:8 B:2
• Conservation: PhyloP100: -0.747
• Publications: 3 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: Likely_benign. The variant received -5 ACMG points.

• BP4: Computational evidence support a benign effect (MetaRNN=0.060884744).
• BS1: Variant frequency is greater than expected in population mid. GnomAdExome4 allele frequency = 0.000015 (22/1461862) while in subpopulation MID AF = 0.00347 (20/5768). AF 95% confidence interval is 0.0023. There are 1 homozygotes in GnomAdExome4. There are 7 alleles in the male GnomAdExome4 subpopulation. Median coverage is 34. This position passed quality control check. Existence of Clinvar submissions makes me limit the strength of this signal to Supporting

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_000179.3. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	MSH6	NM_000179.3	MANE Select	c.733A>T	p.Ile245Leu	missense	Exon 4 of 10	NP_000170.1
	MSH6	NM_001406795.1		c.829A>T	p.Ile277Leu	missense	Exon 5 of 11	NP_001393724.1
	MSH6	NM_001406813.1		c.739A>T	p.Ile247Leu	missense	Exon 4 of 10	NP_001393742.1

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	MSH6	ENST00000234420.11	TSL:1 MANE Select	c.733A>T	p.Ile245Leu	missense	Exon 4 of 10	ENSP00000234420.5
	MSH6	ENST00000445503.5	TSL:1	n.*80A>T		non_coding_transcript_exon	Exon 3 of 9	ENSP00000405294.1
	MSH6	ENST00000445503.5	TSL:1	n.*80A>T		3_prime_UTR	Exon 3 of 9	ENSP00000405294.1

Frequencies

GnomAD3 genomes AF: 0.0000197 AC: 3 AN: 152218 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.0000241

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.0000294

Gnomad OTH AF: 0.00

GnomAD2 exomes AF: 0.00000398 AC: 1 AN: 251164 AF XY: 0.00000737

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 FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00000881

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.0000150 AC: 22 AN: 1461862 Hom.: 1 Cov.: 34 AF XY: 0.00000963 AC XY: 7 AN XY: 727234

African (AFR) AF: 0.00 AC: 0 AN: 33480

American (AMR) AF: 0.0000224 AC: 1 AN: 44724

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26136

East Asian (EAS) AF: 0.00 AC: 0 AN: 39700

South Asian (SAS) AF: 0.00 AC: 0 AN: 86256

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53396

Middle Eastern (MID) AF: 0.00347 AC: 20 AN: 5768

European-Non Finnish (NFE) AF: 8.99e-7 AC: 1 AN: 1112006

Other (OTH) AF: 0.00 AC: 0 AN: 60396

GnomAD4 genome AF: 0.0000197 AC: 3 AN: 152218 Hom.: 0 Cov.: 32 AF XY: 0.0000134 AC XY: 1 AN XY: 74376

African (AFR) AF: 0.0000241 AC: 1 AN: 41452

American (AMR) AF: 0.00 AC: 0 AN: 15280

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3472

East Asian (EAS) AF: 0.00 AC: 0 AN: 5206

South Asian (SAS) AF: 0.00 AC: 0 AN: 4830

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10622

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 316

European-Non Finnish (NFE) AF: 0.0000294 AC: 2 AN: 68038

Other (OTH) AF: 0.00 AC: 0 AN: 2090

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.0000453

ExAC AF: 0.00000824 AC: 1

EpiCase AF: 0.00

EpiControl AF: 0.000119

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:8 Benign:2

Revision: criteria provided, conflicting classifications

Submissions by phenotype

not provided Uncertain:4

Breakthrough Genomics, Breakthrough Genomics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: not provided

Jun 27, 2023

Revvity Omics, Revvity

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Apr 04, 2023

GeneDx

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports that this missense variant does not alter protein structure/function; This variant is associated with the following publications: (PMID: 23621914, 24123366, 23729658, 28874130, 30733081, 21437237, 31841383)

May 14, 2018

Quest Diagnostics Nichols Institute San Juan Capistrano

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Lynch syndrome 5 Uncertain:2

Jul 07, 2023

KCCC/NGS Laboratory, Kuwait Cancer Control Center

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces isoleucine with leucine at codon 245 of the MSH6 protein (p.Ile245Leu). The isoleucine residue is weakly conserved and there is a small physicochemical difference between isoleucine and leucine. This variant is present in population databases (rs762168786, ExAC 0.002%). This variant has been reported in an individual affected with colorectal cancer in the Universal Mutation Database (PMID: 23729658) and in a family with suspected Lynch syndrome (PMID: 28874130). ClinVar has 5 entries for this mutation and all are listed as variant of unknown significance. An algorithm developed specifically for the MSH6 gene suggests that this missense change is likely to be tolerated (PMID: 23621914). However, this prediction has not been confirmed by published functional studies and its clinical significance is uncertain. 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.

Apr 27, 2017

Illumina Laboratory Services, Illumina

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant was observed as part of a predisposition screen in an ostensibly healthy population. A literature search was performed for the gene, cDNA change, and amino acid change (where applicable). No publications were found based on this search. Allele frequency data from public databases did not allow this variant to be ruled in or out of causing disease. Therefore, this variant is classified as a variant of unknown significance.

Hereditary cancer-predisposing syndrome Uncertain:1 Benign:1

Jun 15, 2025

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The p.I245L variant (also known as c.733A>T), located in coding exon 4 of the MSH6 gene, results from an A to T substitution at nucleotide position 733. The isoleucine at codon 245 is replaced by leucine, an amino acid with highly similar properties. This alteration has been reported in one family from Uruguay who met Amsterdam II criteria and/or Bethesda guidelines (Rossi BM et al. BMC Cancer, 2017 Sep;17:623). This amino acid position is not well 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.

Mar 11, 2025

Color Diagnostics, LLC DBA Color Health

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

not specified Uncertain:1

Dec 11, 2017

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

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Variant summary: The MSH6 c.733A>T (p.Ile245Leu) variant involves the alteration of a non-conserved nucleotide. 5/5 in silico tools used predict a benign outcome for this variant and the variant is located outside of any known functional domain, however no functional studies confirming these predictions have been published at the time of evaluation. This variant was found in 1/215148 control chromosomes at a frequency of 0.0000046, which does not exceed the maximal expected allele frequency of a pathogenic MSH6 variant (0.0001421). This variant has been reported in at least one LS patient without strong evidence supporting causality (Rossi_2017). In addition, multiple clinical diagnostic laboratories classified this variant as uncertain significance. Taken together, this variant is classified as VUS.

Hereditary nonpolyposis colorectal neoplasms Benign:1

Dec 29, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.077
BayesDel_addAF	Benign	-0.046	T
BayesDel_noAF	Benign	-0.30
CADD	Benign	13
DANN	Benign	0.96
DEOGEN2	Benign	0.24	T
Eigen	Benign	-0.68
Eigen_PC	Benign	-0.62
FATHMM_MKL	Benign	0.17	N
LIST_S2	Benign	0.72	T
M_CAP	Benign	0.038	D
MetaRNN	Benign	0.061	T
MetaSVM	Benign	-0.79	T
MutationAssessor	Benign	1.4	L
PhyloP100		-0.75
PrimateAI	Benign	0.39	T
PROVEAN	Benign	-0.21	N
REVEL	Benign	0.19
Sift	Benign	0.32	T
Sift4G	Benign	0.36	T
Polyphen		0.0050	B
Vest4		0.27
MutPred		0.18		Loss of methylation at K246 (P = 0.0499)
MVP		0.62
ClinPred		0.033	T
GERP RS		2.2
Varity_R		0.064
gMVP		0.047
Mutation Taster		=84/16	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: rs762168786; hg19: chr2-48025855;