rs1553333738

chr2-47806628-G-GAATC

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.3980_3983dup(p.Leu1330ValfsTer12) variant causes a frameshift change. The variant allele was found at a frequency of 0.00000206 in 1,459,480 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Likely pathogenic (★★).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000021 (0 hom.)
• Consequence: MSH6 NM_000179.3 frameshift
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:13
• Conservation: PhyloP100: 4.12

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 does not undergo nonsense mediated mRNA decay. Variant is located in the 3'-most 50 bp of the penultimate exon, not predicted to undergo nonsense mediated mRNA decay. There are 34 pathogenic variants in the truncated region.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 2-47806628-G-GAATC is Pathogenic according to our data. Variant chr2-47806628-G-GAATC is described in ClinVar as [Likely_pathogenic]. Clinvar id is 184998.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
MSH6	NM_000179.3	c.3980_3983dup	p.Leu1330ValfsTer12	frameshift_variant	9/10	ENST00000234420.11

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
MSH6	ENST00000234420.11	c.3980_3983dup	p.Leu1330ValfsTer12	frameshift_variant	9/10	1	NM_000179.3	P4

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD3 exomes AF: 0.00000405 AC: 1 AN: 246946 Hom.: 0 AF XY: 0.00000748 AC XY: 1 AN XY: 133762

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 SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00000897

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000206 AC: 3 AN: 1459480 Hom.: 0 Cov.: 35 AF XY: 0.00000275 AC XY: 2 AN XY: 726138

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.0000224

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: 0.00000180

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:13

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not provided Pathogenic:3

Pathogenic, criteria provided, single submitter	clinical testing	GeneDx	Jul 25, 2023	Frameshift variant predicted to result in protein truncation in a gene for which loss-of-function is a known mechanism of disease; Observed as homozygous in a patient with constitutional mismatch repair deficiency (CMMR-D) (Toledano et al., 2019); Observed as heterozygous in individuals with a personal or family history consistent with pathogenic variants in this gene (Baglietto et al., 2010; Yang et al., 2021); Not observed at a 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: 31730237, 28152038, 31447099, 34148862, 36988593, 32844218, 34086170, 20028993, 29922827, 32030746, 31501241, 33977078) -
Likely pathogenic, no assertion criteria provided	research	Mayo Clinic Laboratories, Mayo Clinic	-	- -
Pathogenic, criteria provided, single submitter	clinical testing	CeGaT Center for Human Genetics Tuebingen	Jul 01, 2019	- -

Lynch syndrome 5 Pathogenic:2

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. -
Likely pathogenic, criteria provided, single submitter	clinical testing	MGZ Medical Genetics Center	Jul 06, 2021	- -

Hereditary cancer-predisposing syndrome Pathogenic:2

Pathogenic, criteria provided, single submitter	clinical testing	Ambry Genetics	Jun 25, 2021	The c.3980_3983dupATCA pathogenic mutation, located in coding exon 9 of the MSH6 gene, results from a duplication of ATCA at position 3980 to 3983, causing a translational frameshift with a predicted alternate stop codon (p.L1330Vfs*12). This alteration was identified once from a pool of Scottish probands with either colon or endometrial cancer diagnosed before age 55 (Baglietto L et al. J Natl Cancer Inst. 2010 Feb 3;102(3):193-201) and was reported homozygous in an individual with CMMRD (Shapira Rootman M et al. Clin Genet, 2020 02;97:296-304). In addition to the clinical data presented in the literature, this alteration is expected to result in loss of function by premature protein truncation. 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 inserts 4 nucleotides in exon 9 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 been identified in 1/246946 chromosomes 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. -

Carcinoma of colon Pathogenic:1

Pathogenic, no assertion criteria provided

clinical testing

Department of Pathology and Laboratory Medicine, Sinai Health System

-

The MSH6 p.Leu1330ValfsX12 variant was identified in 3 of 69962 proband chromosomes (frequency: 0.00004) from individuals or families with lynch syndrome (Espenschied 2017). The variant was also identified in dbSNP (ID: rs786204180) as N/A, ClinVar (classified as pathogenic by Ambry Genetics, Invitae, GenDxl; classified as likely pathogenic by Mayo Clinic), Clinvitae (classified as pathogenic by ClinVar and Invitae), databases. The variant was not identified in UMD-LSDB, Insight Colon Cancer Gene Variant Database, Zhejiang Colon Cancer Database, Mismatch Repair Genes Variant Database, Insight Hereditary Tumors Database, databases. The variant was not identified in the 1000 Genomes Project, the NHLBI GO Exome Sequencing Project or the Exome Aggregation Consortium (August 8th 2016) control databases. The c.3980_3983dup variant is predicted to cause a frameshift, which alters the protein's amino acid sequence beginning at codon 1330 and leads to a premature stop codon at position 1341. 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 nonpolyposis colon cancer Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

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

May 01, 2021

Variant summary: MSH6 c.3980_3983dupATCA (p.Leu1330ValfsX12) 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 allele was found at a frequency of 4e-06 in 246946 control chromosomes. c.3980_3983dupATCA has been reported in the literature in multiple individuals affected with Lynch syndrome and features of CMMRD (constitutional mismatch repair deficiency) (example, Baglietto_2010, Gardes_2012, Epsenschied_2017, Toledano_2019, Rootman_2020, Dong_2020). These data indicate that the variant is very likely to be associated with disease. Six 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. Based on the evidence outlined above, the variant was classified as pathogenic. -

Lynch syndrome Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine

Oct 27, 2021

The p.Leu1330fs (c.3984_3987dupATCA) variant in MSH6 has been reported in at least 1 individual with Lynch syndrome-associated cancers (Baglietto 2010 PMID: 20028993) and in homozygous state in 1 individual with constitutional mismatch repair deficiency syndrome (CMMRD; Shapira Rootman 2020 PMID: 31730237, Toledano 2020 PMID: 31501241). Additionally, another variant at this position (c.3984_3987dupGTCA) leading to the same frameshift has been described as an Ashkenazi Jewish founder variant and has been shown to cause loss of expression of MSH6 protein (Goldberg 2010 PMID: 19851887). This variant has also been reported by other clinical laboratories in ClinVar (Variation ID 184998) and has been identified in 1/111536 European chromosomes by gnomAD (http://gnomad.broadinstitute.org). This variant is predicted to cause a frameshift, which alters the protein’s amino acid sequence beginning at position 1330 and leads to a premature termination codon 12 amino acids downstream. Although this termination codon occurs within the last exon and is more likely to escape nonsense mediated decay (NMD), the available evidence from the other Ashkenazi Jewish founder variant shows that the variant ultimately leads to loss of function. Heterozygous loss of function of the MSH6 gene is an established disease mechanism in individuals with Lynch syndrome. In summary, this variant meets criteria to be classified as pathogenic for Lynch syndrome in an autosomal dominant manner based upon the predicted impact to the protein and the presence of an established pathogenic variant with the same amino acid change. ACMG/AMP Criteria applied: PS1; PVS1_Strong, PM2_Supporting. -

Gastric cancer Pathogenic:1

Pathogenic, no assertion criteria provided

research

Laboratory for Genotyping Development, RIKEN

Jul 01, 2021

- -

Hereditary nonpolyposis colorectal neoplasms Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Invitae

Dec 09, 2023

This sequence change creates a premature translational stop signal (p.Leu1330Valfs*12) in the MSH6 gene. While this is not anticipated to result in nonsense mediated decay, it is expected to disrupt the last 31 amino acid(s) of the MSH6 protein. This variant is present in population databases (rs786204180, gnomAD 0.0009%). This premature translational stop signal has been observed in individual(s) with clinical features of MSH6-related conditions (PMID: 14520694, 19851887, 20028993, 24440087). It has also been observed to segregate with disease in related individuals. ClinVar contains an entry for this variant (Variation ID: 184998). For these reasons, this variant has been classified as Pathogenic. -

Endometrial carcinoma Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Baylor Genetics

Jun 21, 2022

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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: rs1553333738; hg19: chr2-48033767;