chr2-47804948-C-A

Position:

• chr2-47804948-C-A

Variant summary

Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PVS1 PM2 PP5_Very_Strong

The NM_000179.3(MSH6):​c.3477C>A​(p.Tyr1159*) variant causes a stop gained change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000197 in 152,192 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Likely pathogenic (★★). Variant results in nonsense mediated mRNA decay.

• Frequency: Genomes: 𝑓 0.000020 (0 hom., cov: 32)
• Consequence: MSH6 NM_000179.3 stop_gained
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:12
• Conservation: PhyloP100: -1.41

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]

MSH6 (HGNC:):

ACMG classification

Verdict is Pathogenic. Variant got 18 ACMG points.

• PVS1: Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 2-47804948-C-A is Pathogenic according to our data. Variant chr2-47804948-C-A is described in ClinVar as [Likely_pathogenic]. Clinvar id is 92577.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr2-47804948-C-A is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
MSH6	NM_000179.3	c.3477C>A	p.Tyr1159*	stop_gained	6/10	ENST00000234420.11	NP_000170.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
MSH6	ENST00000234420.11	c.3477C>A	p.Tyr1159*	stop_gained	6/10	1	NM_000179.3	ENSP00000234420.5

Frequencies

GnomAD3 genomes AF: 0.0000197 AC: 3 AN: 152192 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.00

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: 0.0000441

Gnomad OTH AF: 0.00

GnomAD4 exome Cov.: 31

GnomAD4 genome AF: 0.0000197 AC: 3 AN: 152192 Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0 AN XY: 74352

Gnomad4 AFR AF: 0.00

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.0000441

Gnomad4 OTH AF: 0.00

Bravo AF: 0.0000151

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:12

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not provided Pathogenic:3

Pathogenic, criteria provided, single submitter	clinical testing	Eurofins Ntd Llc (ga)	Jun 07, 2013	- -
Pathogenic, no assertion criteria provided	research	Mayo Clinic Laboratories, Mayo Clinic	-	- -
Pathogenic, criteria provided, single submitter	clinical testing	GeneDx	Mar 12, 2024	Nonsense 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; Truncating variants in this gene are considered pathogenic by a well-established clinical consortium and/or database; Observed in individuals with a personal and/or family history consistent with pathogenic variants in this gene (PMID: 21642682, 21868491, 33693762); Not observed at significant frequency in large population cohorts (gnomAD); This variant is associated with the following publications: (PMID: 21642682, 21868491, 28502729, 32719484, 33630411, 36974006, 33693762) -

Hereditary cancer-predisposing syndrome Pathogenic:2

Pathogenic, criteria provided, single submitter	clinical testing	Ambry Genetics	May 19, 2022	The p.Y1159* pathogenic mutation (also known as c.3477C>A), located in coding exon 6 of the MSH6 gene, results from a C to A substitution at nucleotide position 3477. This changes the amino acid from a tyrosine to a stop codon within coding exon 6. This mutation was identified in a single French family suspected of Lynch syndrome in one study (Bonadona V et al. JAMA 2011 Jun;305:2304-10). 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. -
Pathogenic, criteria provided, single submitter	clinical testing	Color Diagnostics, LLC DBA Color Health	Jan 15, 2020	This variant changes 1 nucleotide in exon 6 of the MSH6 gene, creating a 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. -

Lynch syndrome 5 Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Myriad Genetics, Inc.

Aug 23, 2023

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

Carcinoma of colon Pathogenic:1

Likely pathogenic, no assertion criteria provided

clinical testing

Department of Pathology and Laboratory Medicine, Sinai Health System

-

The MSH6 p.Tyr1159* variant was identified in 2 of 5260 proband chromosomes (frequency: 0.0004) from individuals or families with colon cancer (Bonadona 2011, Perez-Cabornell 2011). The variant was also identified in dbSNP (ID: rs398123231) as “With Pathogenic, Uncertain significance allele"), ClinVar (classified as pathogenic by Invitae, Ambry Genetics, and two other clinical laboratories), UMD-LSDB (12x as causal), and in Insight InSiGHT Hereditary Tumors databases. The variant was not identified in the COGR, Cosmic, MutDB, Zhejiang University Database, and or Mismatch Repair Genes Variant databases. The variant was not identified in the following control databases: the 1000 Genomes Project, the NHLBI GO Exome Sequencing Project, the Exome Aggregation Consortium (August 8th 2016), or the Genome Aggregation Database (Feb 27, 2017). The p.Tyr1159* variant leads to a premature stop codon at position 1159, which is predicted to lead to 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 this 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. -

Hereditary nonpolyposis colon cancer Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

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

May 02, 2022

Variant summary: MSH6 c.3477C>A (p.Tyr1159X) results in a premature termination codon, predicted to cause a truncation of the encoded protein or absence of the protein due to nonsense mediated decay, which are commonly known mechanisms for disease. Truncations downstream of this position have been classified as pathogenic by our laboratory. The variant was absent in 251396 control chromosomes. c.3477C>A has been reported in the literature in individuals affected with Lynch Syndrome (example, Bonadona_2011, Perez-Carbonell_2011, Marignol_2008, Rey_2017, Ferrer-Avargues_2021, Post_2021). These data indicate that the variant is likely to be associated with disease. Four clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014 without evidence for independent evaluation. All laboratories classified the variant as pathogenic/likely pathogenic. Based on the evidence outlined above, the variant was classified as pathogenic. -

Lynch syndrome Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

Genetics and Molecular Pathology, SA Pathology

Jul 01, 2021

- -

Lynch-like syndrome Pathogenic:1

Pathogenic, no assertion criteria provided

clinical testing

Constitutional Genetics Lab, Leon Berard Cancer Center

Jul 01, 2019

- -

Hereditary nonpolyposis colorectal neoplasms Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Dec 01, 2023

This sequence change creates a premature translational stop signal (p.Tyr1159*) 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 Lynch syndrome-associated cancers (PMID: 21642682, 21868491). ClinVar contains an entry for this variant (Variation ID: 92577). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. For these reasons, this variant has been classified as Pathogenic. -

Endometrial carcinoma Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Baylor Genetics

Aug 21, 2023

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.40	D
BayesDel_noAF	Pathogenic	0.33
CADD	Uncertain	24
DANN	Benign	0.97
Eigen	Benign	-0.43
Eigen_PC	Benign	-0.79
FATHMM_MKL	Benign	0.30	N
Vest4		0.94
GERP RS		-8.6
RBP_binding_hub_radar		0.97
RBP_regulation_power_radar		2.8

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.020		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: rs398123231; hg19: chr2-48032087;