NM_000179.3:c.2079dupA

Variant names:

• chr2-47800056-C-CA
• rs267608083
• NM_000179.3:c.2079dupA

Variant summary

Our verdict is Pathogenic. The variant received 16 ACMG points: 16P and 0B. PVS1 PP5_Very_Strong

The NM_000179.3(MSH6):​c.2079dupA​(p.Cys694MetfsTer4) variant causes a frameshift change. The variant allele was found at a frequency of 0.00000682 in 1,613,880 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Pathogenic (★★). Synonymous variant affecting the same amino acid position (i.e. C694C) has been classified as Likely benign. Variant results in nonsense mediated mRNA decay.

• Frequency:
  • Genomes: 𝑓 0.0000066 (0 hom., cov: 32)
  • Exomes 𝑓: 0.0000068 (0 hom.)
• Consequence: MSH6 NM_000179.3 frameshift
• Clinical Significance: Pathogenic criteria provided, multiple submitters, no conflicts P:12
• Conservation: PhyloP100: 5.79
• Publications: 10 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: Pathogenic. The variant received 16 ACMG points.

• PVS1: Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
• PP5: Variant 2-47800056-C-CA is Pathogenic according to our data. Variant chr2-47800056-C-CA is described in ClinVar as Pathogenic. ClinVar VariationId is 187516.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
MSH6	NM_000179.3	c.2079dupA	p.Cys694MetfsTer4	frameshift_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.2079dupA	p.Cys694MetfsTer4	frameshift_variant	Exon 4 of 10	1	NM_000179.3	ENSP00000234420.5

Frequencies

GnomAD3 genomes AF: 0.00000658 AC: 1 AN: 152022 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.0000242

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: 0.00

Gnomad OTH AF: 0.00

GnomAD4 exome AF: 0.00000684 AC: 10 AN: 1461858 Hom.: 0 Cov.: 34 AF XY: 0.0000110 AC XY: 8 AN XY: 727228

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

American (AMR) AF: 0.00 AC: 0 AN: 44722

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26134

East Asian (EAS) AF: 0.00 AC: 0 AN: 39698

South Asian (SAS) AF: 0.00 AC: 0 AN: 86258

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

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5768

European-Non Finnish (NFE) AF: 0.00000899 AC: 10 AN: 1112006

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

GnomAD4 genome AF: 0.00000658 AC: 1 AN: 152022 Hom.: 0 Cov.: 32 AF XY: 0.0000135 AC XY: 1 AN XY: 74258

African (AFR) AF: 0.0000242 AC: 1 AN: 41392

American (AMR) AF: 0.00 AC: 0 AN: 15260

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3468

East Asian (EAS) AF: 0.00 AC: 0 AN: 5184

South Asian (SAS) AF: 0.00 AC: 0 AN: 4824

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10588

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

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 67990

Other (OTH) AF: 0.00 AC: 0 AN: 2088

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.00000378

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:12

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not provided Pathogenic:3

-

Department of Pathology and Laboratory Medicine, Sinai Health System

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: clinical testing

The MSH6 p.Cys694Metfs*4 variant was identified in 2 of 3472 proband chromosomes (frequency: 0.0006) from individuals or families with colorectal, cervical, or prostate cancer (Hansen 2017, Shirts 2015). The variant was also identified in dbSNP (ID: rs267608083) as “With Pathogenic allele”, ClinVar (classified as pathogenic by Ambry Genetics, Invitae, GeneDx and one other clinical laboratory), UMD-LSDB (1x causal), and Insight Hereditary Tumors Database (2x). The variant was not identified in the COGR, Cosmic, Zhejiang University Database, or Mismatch Repair Genes Variant database. The variant was not identified in the following control databases: the Exome Aggregation Consortium (August 8th 2016) or the Genome Aggregation Database (Feb 27, 2017). The c.2079dup variant is predicted to cause a frameshift, which alters the protein's amino acid sequence beginning at codon 694 and leads to a premature stop codon at position 697. This alteration is then predicted to result in a truncated or absent protein and loss of function. Loss of function variants of the MSH6 gene are an established mechanism of disease in Lynch syndrome and is the type of variant expected to cause the disorder. In summary, based on the above information this variant meets our laboratory’s criteria to be classified as pathogenic. -

Aug 01, 2025

GeneDx

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Reported in individuals with personal and/or a family history of colorectal cancer (PMID: 26845104, 28195393); Frameshift variant predicted to result in protein truncation or nonsense mediated decay in a gene for which loss of function is a known mechanism of disease; Not observed at significant frequency in large population cohorts (gnomAD); Truncating variants in this gene are considered pathogenic by a well-established clinical consortium and/or database; This variant is associated with the following publications: (PMID: 26845104, 28195393, 28944238, 31297992, 30787465, 33087929, 35626060) -

Oct 31, 2017

Quest Diagnostics Nichols Institute San Juan Capistrano

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Hereditary cancer-predisposing syndrome Pathogenic:3

Aug 30, 2024

Ambry Genetics

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The c.2079dupA pathogenic mutation, located in coding exon 4 of the MSH6 gene, results from a duplication of A at nucleotide position 2079, causing a translational frameshift with a predicted alternate stop codon (p.C694Mfs*4). This mutation has been detected in multiple colorectal cancer patients (DeRycke MS et al. Mol Genet Genomic Med. 2017 Jul 23;5:553-569; Hansen MF et al. Clin Genet. 2017 Oct;92:405-414). Of note, this alteration is designated as c.2073_2074insA in published literature. This variant is considered to be rare based on population cohorts in the Genome Aggregation Database (gnomAD). In addition to the clinical data presented in the literature, this alteration is expected to result in loss of function by premature protein truncation or nonsense-mediated mRNA decay. As such, this alteration is interpreted as a disease-causing mutation. -

Jan 15, 2020

Color Diagnostics, LLC DBA Color Health

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant inserts 1 nucleotide in exon 4 of the MSH6 gene, creating a frameshift and premature translation stop signal. This variant is expected to result in an absent or non-functional protein product. This variant has not been identified in the general population by the Genome Aggregation Database (gnomAD). Loss of MSH6 function is a known mechanism of disease (clinicalgenome.org). Based on the available evidence, this variant is classified as Pathogenic. -

Apr 20, 2021

Sema4, Sema4

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: curation

- -

Lynch syndrome Pathogenic:2

Nov 20, 2015

University of Washington Department of Laboratory Medicine, University of Washington

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Oct 28, 2021

Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The p.Cys694MetfsX4 variant in MSH6 has been reported in 2 individuals with colorectal cancer (DeRycke 2017 PMID: 28944238, Hansen 2017 PMID: 28195393, Xavier 2019 PMID: 31297992) and in 1 individual with a family history of Lynch-associated tumors (Shirts 2016 PMID: 26845104). This variant has also been reported by other clinical laboratories in ClinVar (Variation ID 187516) and is absent from large population studies. This variant is predicted to cause a frameshift, which alters the protein’s amino acid sequence beginning at position 694 and leads to a premature termination codon 4 amino acids downstream. This alteration is then predicted to lead to a truncated or absent protein. Loss of function of the MSH6 gene is an established disease mechanism in autosomal dominant Lynch syndrome. In summary, this variant meets criteria to be classified as pathogenic for autosomal dominant Lynch syndrome. ACMG/AMP Criteria applied: PVS1, PM2_Supporting, PS4_Supporting. -

Lynch syndrome 5 Pathogenic:1

Aug 16, 2023

Myriad Genetics, Inc.

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant is considered pathogenic. This variant creates a frameshift predicted to result in premature protein truncation. -

Inherited MMR deficiency (Lynch syndrome) Pathogenic:1

Jul 04, 2024

Genomics and Molecular Medicine Service, East Genomic Laboratory Hub, NHS Genomic Medicine Service

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

PVS1,PS4_Very Strong,PP4 -

Hereditary nonpolyposis colorectal neoplasms Pathogenic:1

Dec 12, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change creates a premature translational stop signal (p.Cys694Metfs*4) in the MSH6 gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in MSH6 are known to be pathogenic (PMID: 18269114, 24362816). This variant is not present in population databases (gnomAD no frequency). This premature translational stop signal has been observed in individual(s) with colorectal cancer (PMID: 21520333, 28195393). Invitae Evidence Modeling of clinical and family history, age, sex, and reported ancestry of multiple individuals with this MSH6 variant has been performed. This variant is expected to be pathogenic with a positive predictive value of at least 99%. This is a validated machine learning model that incorporates the clinical features of 1,370,736 individuals referred to our laboratory for MSH6 testing. ClinVar contains an entry for this variant (Variation ID: 187516). For these reasons, this variant has been classified as Pathogenic. -

Endometrial carcinoma Pathogenic:1

Nov 11, 2022

Baylor Genetics

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
PhyloP100		5.8
Mutation Taster		=0/200	disease causing (ClinVar)

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: rs267608083; hg19: chr2-48027195;