NM_000179.3:c.1109T>C
Variant summary
Our verdict is Pathogenic. The variant received 11 ACMG points: 11P and 0B. PM2PP3PP5_Very_Strong
The NM_000179.3(MSH6):c.1109T>C(p.Leu370Ser) variant causes a missense change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Likely pathogenic (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. L370V) has been classified as Uncertain significance.
Frequency
Consequence
NM_000179.3 missense
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
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ACMG classification
Our verdict: Pathogenic. The variant received 11 ACMG points.
Transcripts
RefSeq
| Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | MANE | Protein | UniProt |
|---|---|---|---|---|---|---|---|---|
| MSH6 | NM_000179.3 | c.1109T>C | p.Leu370Ser | missense_variant | Exon 4 of 10 | ENST00000234420.11 | NP_000170.1 |
Ensembl
| Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | TSL | MANE | Protein | Appris | UniProt |
|---|---|---|---|---|---|---|---|---|---|---|
| MSH6 | ENST00000234420.11 | c.1109T>C | p.Leu370Ser | missense_variant | Exon 4 of 10 | 1 | NM_000179.3 | ENSP00000234420.5 |
Frequencies
GnomAD3 genomes Cov.: 32
GnomAD4 exome Cov.: 34
GnomAD4 genome Cov.: 32
ClinVar
Submissions by phenotype
Lynch syndrome Pathogenic:4
Co-segregation likelihood ratio >250, shared with 3th cousin with loss of MSH6 and others with Lynch cancers in large pedigree, likelihood ration for cosegregation >250 -
The p.Leu370Ser variant in MSH6 has been identified in at least 14 individuals with Lynch syndrome associated cancers and segregated with disease in 4 affected relatives from 2 families (Egoavil 2013, Batte 2014, Pearlman 2017, GeneDx pers. comm., Ambry pers. comm.). In addition, tumors sampled from at least 10 individuals lacked MSH6 expression and/or showed high microsatellite instability, while at least one tumor showed normal MSH6 expression and/or low microsatellite instability. This variant has also been reported by other clinical laboratories in ClinVar (Variation ID #89172) and was absent from large population studies. In summary, although additional studies are required to fully establish its clinical significance, this variant meets criteria to be classified as likely pathogenic for autosomal dominant Lynch syndrome. ACMG/AMP Criteria applied: PS4, PM2, PP1. -
This missense variant replaces leucine with serine at codon 370 of the MSH6 protein. Computational prediction suggests that this variant may have deleterious impact on protein structure and function (internally defined REVEL score threshold >= 0.7, PMID: 27666373). To our knowledge, functional studies have not been reported for this variant. This variant has been observed in individuals affected with Lynch syndrome (PMID: 32652087, 33393477), with endometrial cancer and/or colorectal cancer (PMID: 24933100, 24244552, 28765196, 30019097), or unspecified cancers (PMID: 28765196). Moreover, it has been observed to segregate with Lynch syndrome related cancers in one family (PMID: 27978560). In addition, a multifactorial likelihood model using in silico data have suggested this variant have a high probability of being deleterious (PMID: 23621914). This variant has not been identified in the general population by the Genome Aggregation Database (gnomAD). Based on the available evidence, this variant is classified as Likely Pathogenic. -
The c.1109T>C (p.Leu370Ser) variant in the MSH6 gene is located on the exon 4 and is predicted to replace leucine with serine at codon 370 (p.Leu370Ser). The variant has been reported in multiple individuals with Lynch syndrome-associated cancers (PMID: 32652087, 34994648, 30019097, 24933100, 24244552) and segregating with hereditary cancer syndrome in a family (PMID: 27978560). The variant is reported in ClinVar (ID: 89172). The variant is absent in the general population database (gnomAD). Computational prediction algorithms suggest a deleterious impact for this variant (REVEL score 0.811). Therefore, the c.1109T>C (p.Leu370Ser) variant in the MSH6 gene has been classified as likely pathogenic. -
not provided Pathogenic:4
Observed in patients with Lynch-related cancers and tumor studies consistent with pathogenic variants in this gene (PMID: 24244552, 24933100, 27978560, 30019097, 32652087, 33393477); Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; This variant is associated with the following publications: (PMID: 24933100, 26333163, 23621914, 27978560, 30019097, 30695780, 32652087, 32719484, 35366121, 31391288, 17531815, 21120944, 24244552, 33393477, 36243179, 37030500, 37751191, 37833309, 37751715, 34994648) -
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PP3, PP4, PM2, PS4_moderate -
The MSH6 c.1109T>C (p.Leu370Ser) variant has been reported in the published literature in multiple individuals affected with Lynch syndrome including colorectal cancer and endometrial cancer (PMIDs: 37751191 (2024), 37833309 (2023), 34994648 (2021), 33393477 (2021), 31391288 (2020), 32652087 (2020), 30019097 (2019), 27978560 (2016), 24933100 (2014), 24244552 (2013)). It was identified in molecular studies examining mismatch repair protein-deficient non-neoplastic colonic crypts and endometrial glands that were associated with underlying Lynch syndrome (PMID: 37030500 (2023)). Co-segregation of the variant with Lynch syndrome was observed in a large family (PMID: 37751715 (2023)). This variant has not been reported in large, multi-ethnic general populations (Genome Aggregation Database, http://gnomad.broadinstitute.org). Analysis of this variant using bioinformatics tools for the prediction of the effect of amino acid changes on protein structure and function yielded predictions that this variant is damaging. Based on the available information, this variant is classified as pathogenic. -
Hereditary cancer-predisposing syndrome Pathogenic:2
This missense variant replaces leucine with serine at codon 370 of the MSH6 protein. Computational prediction suggests that this variant may have deleterious impact on protein structure and function (internally defined REVEL score threshold >= 0.7, PMID: 27666373). To our knowledge, functional studies have not been reported for this variant. This variant has been observed in individuals affected with Lynch syndrome (PMID: 32652087, 33393477), with endometrial cancer and/or colorectal cancer (PMID: 24933100, 24244552, 28765196, 30019097), or unspecified cancers (PMID: 28765196). Moreover, it has been observed to segregate with Lynch syndrome related cancers in one family (PMID: 27978560). In addition, a multifactorial likelihood model using in silico data have suggested this variant have a high probability of being deleterious (PMID: 23621914). This variant has not been identified in the general population by the Genome Aggregation Database (gnomAD). Based on the available evidence, this variant is classified as Likely Pathogenic. -
The p.L370S pathogenic mutation (also known as c.1109T>C), located in coding exon 4 of the MSH6 gene, results from a T to C substitution at nucleotide position 1109. The leucine at codon 370 is replaced by serine, an amino acid with dissimilar properties. This variant has been found to co-segregate with disease in HNPCC/Lynch syndrome families (Ambry internal data; Pearlman R et al. JAMA Oncol. 2017 Apr;3:464-471). This variant was detected in 1/173 unselected Spanish women with endometrial cancer; tumor studies for this individual showed microsatellite stability (MSS) with loss of MSH6 protein expression, but intact MSH2 protein expression (Egoavil C et al. PLoS One. 2013 Nov 7;8(11):e79737). This alteration was also detected in a 53-year-old woman whose endometrial cancer showed low microsatellite instability (MSI-L) with normal protein expression for all the mismatch repair proteins; family history was noncontributory (Batte BA et al. Gynecol Oncol. 2014 Aug;134(2):319-25). In addition, this variant has been identified in numerous individuals whose HNPCC/Lynch syndrome-associated tumors demonstrated isolated loss of MSH6 staining on immunohistochemistry and/or had family histories that met Amsterdam II criteria (Ambry internal data). This amino acid position is well conserved in available vertebrate species. In addition, this alteration is predicted to be deleterious by in silico analysis. Based on the supporting evidence, this alteration is interpreted as a disease-causing mutation. -
Lynch syndrome 5 Pathogenic:1
This variant is considered likely pathogenic. 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]. -
Hereditary nonpolyposis colon cancer Pathogenic:1
Variant summary: MSH6 c.1109T>C (p.Leu370Ser) results in a non-conservative amino acid change in the encoded protein sequence. Five of five in-silico tools predict a damaging effect of the variant on protein function. The variant was absent in 250994 control chromosomes (gnomAD). c.1109T>C has been reported in the literature in multiple individuals affected with Lynch Syndrome and endometrial cancer (example, Egoavil_2013, Pearlman_2017, Chen_2020, Li_2020, Hampel_2021). Most of the reported patients were noted with loss of MSH6 expression in tumors by IHC analysis, although one patient was reported with intact MSH6 (Chen_2020). Furthermore, one of these studies reported co-segregation of the variant with disease among two first and second generation relatives within the family (Pearlman_2017). These data indicate that the variant is very likely to be associated with disease. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. Six ClinVar submitters (evaluation after 2014) cite the variant as pathogenic (n=1) and as likely pathogenic (n=5). Based on the evidence outlined above, the variant was classified as pathogenic. -
MSH6-related disorder Pathogenic:1
The MSH6 c.1109T>C variant is predicted to result in the amino acid substitution p.Leu370Ser. This variant has been reported in individuals with colorectal cancer (Pearlman et al. 2017. PubMed ID: 27978560) and endometrial cancer (Egoavil et al. 2013. PubMed ID: 24244552; Batte et al. 2014. PubMed ID: 24933100). At least one tumor showed microsatellite instability and/or abnormal immunohistochemistry (Pearlman et al. 2017. PubMed ID: 27978560). This variant has not been reported in a large population database (http://gnomad.broadinstitute.org), indicating this variant is rare. It is interpreted as pathogenic/likely pathogenic in ClinVar (https://www.ncbi.nlm.nih.gov/clinvar/variation/89172/?new_evidence=true). This variant is interpreted as likely pathogenic. -
Gastric cancer Pathogenic:1
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Hereditary nonpolyposis colorectal neoplasms Pathogenic:1
This sequence change replaces leucine, which is neutral and non-polar, with serine, which is neutral and polar, at codon 370 of the MSH6 protein (p.Leu370Ser). This variant is not present in population databases (gnomAD no frequency). This missense change has been observed in individuals with endometrial cancer and/or colorectal cancer (PMID: 24244552, 24933100, 27978560; internal data). It has also been observed to segregate with disease in related individuals. Invitae Evidence Modeling of clinical and family history, age, sex, and reported ancestry of multiple individuals with this MSH6 variant has been performed. This variant is expected to be pathogenic with a positive predictive value of at least 99%. This is a validated machine learning model that incorporates the clinical features of 1,370,736 individuals referred to our laboratory for MSH6 testing. ClinVar contains an entry for this variant (Variation ID: 89172). An algorithm developed specifically for the MSH6 gene suggests that this missense change is likely to be deleterious (PMID: 23621914). 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