rs267608126

Positions:

• chr2-47806586-T-TATTC

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.3938_3941dup​(p.Gln1314HisfsTer6) variant causes a frameshift change. The variant allele was found at a frequency of 0.00000658 in 152,074 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Pathogenic (★★★). Variant results in nonsense mediated mRNA decay.

• Frequency: Genomes: 𝑓 0.0000066 (0 hom., cov: 32)
• Consequence: MSH6 NM_000179.3 frameshift
• Clinical Significance: Pathogenic reviewed by expert panel P:7
• Conservation: PhyloP100: 6.30

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 2-47806586-T-TATTC is Pathogenic according to our data. Variant chr2-47806586-T-TATTC is described in ClinVar as [Pathogenic]. Clinvar id is 89485.Status of the report is reviewed_by_expert_panel, 3 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
MSH6	NM_000179.3	c.3938_3941dup	p.Gln1314HisfsTer6	frameshift_variant	9/10	ENST00000234420.11	NP_000170.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
MSH6	ENST00000234420.11	c.3938_3941dup	p.Gln1314HisfsTer6	frameshift_variant	9/10	1	NM_000179.3	ENSP00000234420	P4

Frequencies

GnomAD3 genomes AF: 0.00000658 AC: 1 AN: 152074 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: 0.0000147

Gnomad OTH AF: 0.00

GnomAD4 exome Cov.: 35

GnomAD4 genome AF: 0.00000658 AC: 1 AN: 152074 Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0 AN XY: 74282

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: 0.0000147

Gnomad4 OTH AF: 0.00

Bravo AF: 0.00000378

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:7

Revision: reviewed by expert panel

Submissions by phenotype

Lynch syndrome Pathogenic:2

Pathogenic, reviewed by expert panel	research	International Society for Gastrointestinal Hereditary Tumours (InSiGHT)	Sep 05, 2013	Coding sequence variation resulting in a stop codon -
Pathogenic, criteria provided, single submitter	clinical testing	Women's Health and Genetics/Laboratory Corporation of America, LabCorp	Apr 27, 2016	Variant summary: The variant of interest results in a frameshift mutation causes a premature termination codon, a known mechanism for disease, as these types of variants are predicted to cause transcript degradation through nonsense mediated decay or produce a truncated protein. The variant of interest has not been observed in controls (ExAC, 1000 Gs or ESP) and has been reported in an individual diagnosed with endometrial cancer via a publication. A reputable database cites the variant with a classification of "pathogenic." Therefore, taking all available lines of evidence into consideration, the variant of interest is classified as Pathogenic. -

Lynch syndrome 5 Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Myriad Genetics, Inc.

Aug 28, 2023

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

not provided Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Quest Diagnostics Nichols Institute San Juan Capistrano

Aug 20, 2018

- -

Hereditary nonpolyposis colorectal neoplasms Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Dec 27, 2023

This sequence change creates a premature translational stop signal (p.Gln1314Hisfs*6) in the MSH6 gene. While this is not anticipated to result in nonsense mediated decay, it is expected to disrupt the last 47 amino acid(s) of the MSH6 protein. 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: 18269114). ClinVar contains an entry for this variant (Variation ID: 89485). This variant disrupts a region of the MSH6 protein in which other variant(s) (p.Ala1320Glufs*6, p.Leu1330Valfs*12) have been determined to be pathogenic (PMID: 21155762). This suggests that this is a clinically significant region of the protein, and that variants that disrupt it are likely to be disease-causing. For these reasons, this variant has been classified as Pathogenic. -

Hereditary cancer-predisposing syndrome Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Ambry Genetics

May 17, 2024

The c.3938_3941dupTTCA pathogenic mutation, located in coding exon 9 of the MSH6 gene, results from a duplication of TTCA at nucleotide position 3938, causing a translational frameshift with a predicted alternate stop codon (p.Q1314Hfs*6). This alteration occurs at the 3' terminus of theMSH6 gene, is not expected to trigger nonsense-mediated mRNA decay, and only impacts the last 47 amino acids of the protein. However, premature stop codons are typically deleterious in nature and the impacted region is critical for protein function (Ambry internal data). This mutation was reported in a patient with a history of endometrial cancer and a family history that met Amsterdam II criteria (Devlin LA et al. Ulster Med J, 2008 Jan;77:25-30). Based on the supporting evidence, this variant is interpreted as a disease-causing mutation. -

Endometrial carcinoma Pathogenic:1

Pathogenic, no assertion criteria provided

clinical testing

Department of Pathology and Laboratory Medicine, Sinai Health System

-

The MSH6 p.Gln1314HisfsX6 variant was identified in 1 of 536 proband chromosomes (frequency: 0.002) from a cohort of Irish individuals or families with HNPCC or sporadic endometrial cancer. The individual with the variant was an endometrial case meeting Amsterdam II criteria (Devlin_2008_18269114). The variant was also identified in dbSNP (ID: rs267608126) “With Pathogenic allele”, ClinVar (classified pathogenic, reviewed by an expert panel (2013); submitters: InSIGHT, Invitae and Ambry Genetics), Clinvitae (2x), Insight Colon Cancer Gene Variant Database, and Insight Hereditary Tumors Database (1x, class 5). The variant was not identified in Genesight-COGR, Cosmic, MutDB, UMD-LSDB, Zhejiang Colon Cancer Database, Mismatch Repair Genes Variant Database, 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 c.3938_3941dupTTAC variant is predicted to cause a frameshift, which alters the protein's amino acid sequence beginning at codon 1314 and leads to a premature stop codon 6 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. -

Computational scores

Source: dbNSFP v4.3

Splicing

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

LitVar

Other links and lift over

dbSNP: rs267608126; hg19: chr2-48033725;