2-47804952-CCTG-C
Variant summary
Our verdict is Pathogenic. The variant received 13 ACMG points: 13P and 0B. PM1PM2PM4_SupportingPP5_Very_Strong
The NM_000179.3(MSH6):c.3485_3487delCTG(p.Ala1162del) variant causes a disruptive inframe deletion change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Likely pathogenic (★★). Synonymous variant affecting the same amino acid position (i.e. A1162A) has been classified as Likely benign.
Frequency
Consequence
NM_000179.3 disruptive_inframe_deletion
Scores
Clinical Significance
Conservation
Publications
- intellectual developmental disorder with dysmorphic facies and behavioral abnormalitiesInheritance: AD Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), Ambry Genetics, G2P
Genome browser will be placed here
ACMG classification
Our verdict: Pathogenic. The variant received 13 ACMG points.
Transcripts
RefSeq
| Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | MANE | Protein | UniProt |
|---|---|---|---|---|---|---|---|---|
| MSH6 | NM_000179.3 | c.3485_3487delCTG | p.Ala1162del | disruptive_inframe_deletion | Exon 6 of 10 | ENST00000234420.11 | NP_000170.1 |
Ensembl
| Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | TSL | MANE | Protein | Appris | UniProt |
|---|---|---|---|---|---|---|---|---|---|---|
| MSH6 | ENST00000234420.11 | c.3485_3487delCTG | p.Ala1162del | disruptive_inframe_deletion | Exon 6 of 10 | 1 | NM_000179.3 | ENSP00000234420.5 |
Frequencies
GnomAD3 genomes Cov.: 32
GnomAD4 genome Cov.: 32
ClinVar
Submissions by phenotype
Hereditary cancer-predisposing syndrome Pathogenic:2
The c.3485_3487delCTG variant (also known as p.A1162del) is located in coding exon 6 of the MSH6 gene. This variant results from an in-frame CTG deletion at nucleotide positions 3485 to 3487. This results in the in-frame deletion of an alanine at codon 1162. This alteration has been identified in three individuals with endometrial cancer and ages at diagnosis ranged from 45y to 54y. One of the individuals was also diagnosed with rectal cancer at the age of 60y. Tumor results for two of the individuals revealed loss of MSH6 protein expression on immunohistochemistry (IHC) while the third individual had a family history that met Amsterdam criteria (Ambry internal data). The alteration was also reported in a patient with endometrial cancer and rectal cancer diagnosed at the ages of 53y and 61y, respectively. Furthermore, tumor results from the endometrial cancer revealed microsatellite instability (MSI-H) (Goodfellow PJ et al. Proc. Natl. Acad. Sci. U.S.A. 2003 May;100(10: 5908-13). This alteration has also been reported in an individual with a personal history of uterine and breast cancers, and family history of uterine, colon and breast cancers (Schwartz CJ et al. Clin Cancer Res, 2022 Jan;28:404-413). The alanine residue resides in a well-defined functional domain and is adjacent to a helix that contains the MSH6 ATP binding p-loop (Warren JJ et al. Mol. Cell 2007 May;26(4):579-92). This amino acid position is highly conserved in available vertebrate species and the impacted region is critical for protein function (Ambry internal data). This variant is considered to be rare based on population cohorts in the Genome Aggregation Database (gnomAD). In addition, this alteration is predicted to be deleterious by in silico analysis (Choi Y et al. PLoS ONE 2012 ; 7(10):e46688). Based on the majority of available evidence to date, this variant is likely to be pathogenic. -
This variant is an in-frame deletion of an alanine at codon 1162 in the ATPase domain of the MSH6 protein. To our knowledge, functional studies have not been published for this variant. This variant is reported to disrupt protein structure and impact function (ClinVar: SCV004185562.1). This variant has been reported in individuals affected with endometrial cancer, uterine, colorectal, breast cancer, and Lynch syndrome, with multiple tumors demonstrating loss of MSH6 protein via immunohistochemistry and/or high microsatellite instability (PMID: 22658618, 28514183, 28888541, 34667028; ClinVar: SCV000172773.10, SCV000624874.5). However, an individual affected with uterine cancer had tumor data demonstrating microsatellite stability and intact MSH6 protein (PMID: 34667028). This variant has not been identified in the general population by the Genome Aggregation Database (gnomAD). A missense variant affecting codon 1162, c.3485C>A (p.Ala1162Asp), is considered to be disease-causing (ClinVar variation ID: 127587), suggesting that this position is important for the protein function. Loss of MSH6 function is a known mechanism of disease (clinicalgenome.org). Based on the available evidence, this variant is classified as Likely Pathogenic. -
Lynch syndrome 5 Pathogenic:1
This variant is considered pathogenic. Functional studies indicate this variant impacts protein function [Myriad internal data]. This variant is expected to disrupt protein structure [Myriad internal data]. This variant is strongly associated with more severe personal and family histories of cancer, typical for individuals with pathogenic variants in this gene [PMID: 27363726]. -
not provided Pathogenic:1
Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports a deleterious effect on protein structure/function; In-frame deletion of 1 amino acid(s) with an unclear effect on protein function; This variant is associated with the following publications: (PMID: 22658618, 12732731, 23056405, 17531815, 28888541, 28514183, 34667028, Plazzer2024[preprint], 21120944) -
Hereditary nonpolyposis colorectal neoplasms Pathogenic:1
This variant, c.3485_3487del, results in the deletion of 1 amino acid(s) of the MSH6 protein (p.Ala1162del), but otherwise preserves the integrity of the reading frame. This variant is not present in population databases (gnomAD no frequency). This variant has been observed in individuals with Lynch syndrome (PMID: 22658618, 28514183; Invitae; external communication). ClinVar contains an entry for this variant (Variation ID: 140774). Experimental studies and prediction algorithms are not available or were not evaluated, and the functional significance of this variant is currently unknown. This variant disrupts a region of the MSH6 protein in which other variant(s) (p.Ala1162Asp) have been determined to be pathogenic (Invitae). 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. -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at