rs863225406

chr2-47803483-TTC-T

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.3238_3239del(p.Leu1080ValfsTer12) variant causes a frameshift change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000274 in 1,461,880 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Likely pathogenic (★★). Synonymous variant affecting the same amino acid position (i.e. I1079I) has been classified as Likely benign. Variant results in nonsense mediated mRNA decay.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000027 (0 hom.)
• Consequence: MSH6 NM_000179.3 frameshift
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:8
• Conservation: PhyloP100: 0.841

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 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 2-47803483-TTC-T is Pathogenic according to our data. Variant chr2-47803483-TTC-T is described in ClinVar as [Likely_pathogenic]. Clinvar id is 218060.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr2-47803483-TTC-T is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
MSH6	NM_000179.3	c.3238_3239del	p.Leu1080ValfsTer12	frameshift_variant	5/10	ENST00000234420.11

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
MSH6	ENST00000234420.11	c.3238_3239del	p.Leu1080ValfsTer12	frameshift_variant	5/10	1	NM_000179.3	P4

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000274 AC: 4 AN: 1461880 Hom.: 0 AF XY: 0.00000275 AC XY: 2 AN XY: 727236

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: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000360

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:8

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Lynch syndrome Pathogenic:2

Likely pathogenic, criteria provided, single submitter	clinical testing	Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine	Oct 14, 2019	The p.Leu1080ValfsX12 variant in MSH6 has been reported in 1 individual with endometrial cancer (Batte 2014) and was absent from large population studies. This variant has been reported in ClinVar (Variation ID 218060), classified as pathogenic by several clinical labs. This variant is predicted to cause a frameshift, which alters the protein’s amino acid sequence beginning at position 1080 and leads to a premature termination codon 12 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, the p.Leu1080ValfsX12 variant meets criteria to be classified as likely pathogenic for Lynch syndrome. ACMG/AMP criteria applied: PVS1, PM2. -
Pathogenic, no assertion criteria provided	clinical testing	Department of Pathology and Laboratory Medicine, Sinai Health System	-	The p.Leu1080ValfsX12 variant was not identified in the literature nor was it identified in the dbSNP, NHLBI Exome Sequencing Project (Exome Variant Server), Exome Aggregation Consortium (ExAC), Clinvitae, COSMIC, MutDB, “Mismatch Repair Genes Variant Database”, “MMR Gene Unclassified Variants Database”, “InSiGHT Colon Cancer Database”, “Zhejiang Colon Cancer Database”, the ClinVar and UMD databases. The p.Leu1080ValfsX12 deletion variant is predicted to cause a frameshift, which alters the protein's amino acid sequence beginning at codon 1080 and leads to a premature stop codon 12 codons downstream. 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 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 cancer-predisposing syndrome Pathogenic:2

Pathogenic, criteria provided, single submitter	clinical testing	Ambry Genetics	Nov 28, 2023	The c.3238_3239delCT pathogenic mutation, located in coding exon 5 of the MSH6 gene, results from a deletion of two nucleotides at nucleotide positions 3238 to 3239, causing a translational frameshift with a predicted alternate stop codon (p.L1080Vfs*12). This mutation was observed in a patient with MSH6-absent, MSI-H endometrial cancer diagnosed at age 65 who also had a family history of endometrial and colorectal cancer (Batte BA et al. Gynecol. Oncol. 2014 Aug;134:319-25). 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 deletes 2 nucleotides in exon 5 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. -

Lynch syndrome 5 Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Myriad Genetics, Inc.

Aug 22, 2023

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

Gastric cancer Pathogenic:1

Pathogenic, no assertion criteria provided

research

Laboratory for Genotyping Development, RIKEN

Jul 01, 2021

- -

not provided Pathogenic:1

Likely pathogenic, no assertion criteria provided

research

Mayo Clinic Laboratories, Mayo Clinic

-

- -

Hereditary nonpolyposis colorectal neoplasms Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Invitae

Oct 08, 2023

This sequence change creates a premature translational stop signal (p.Leu1080Valfs*12) 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 endometrial cancer (PMID: 24933100). ClinVar contains an entry for this variant (Variation ID: 218060). For these reasons, this variant has been classified as Pathogenic. -

Computational scores

Source: dbNSFP v4.3

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: rs863225406; hg19: chr2-48030622;