rs1060500702
Variant summary
Our verdict is Pathogenic. The variant received 16 ACMG points: 16P and 0B. PM1PM2PP3_StrongPP5_Very_Strong
The NM_000249.4(MLH1):c.440G>A(p.Gly147Glu) 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. G147R) has been classified as Uncertain significance.
Frequency
Consequence
NM_000249.4 missense
Scores
Clinical Significance
Conservation
Publications
- Lynch syndromeInheritance: AD Classification: DEFINITIVE, SUPPORTIVE Submitted by: G2P, ClinGen, Orphanet
- Lynch syndrome 2Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: Ambry Genetics, Genomics England PanelApp
- Muir-Torre syndromeInheritance: AD Classification: DEFINITIVE, STRONG, MODERATE, SUPPORTIVE Submitted by: Genomics England PanelApp, Ambry Genetics, G2P, Orphanet
- mismatch repair cancer syndrome 1Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Ambry Genetics, G2P, Labcorp Genetics (formerly Invitae), Orphanet, ClinGen
- Lynch syndrome 1Inheritance: AD Classification: STRONG Submitted by: Labcorp Genetics (formerly Invitae)
- ovarian cancerInheritance: AD Classification: STRONG Submitted by: Genomics England PanelApp
- malignant pancreatic neoplasmInheritance: AD Classification: MODERATE Submitted by: Genomics England PanelApp
- rhabdomyosarcomaInheritance: AR Classification: MODERATE Submitted by: Genomics England PanelApp
- prostate cancerInheritance: AD Classification: LIMITED Submitted by: Ambry Genetics
- breast cancerInheritance: AD Classification: NO_KNOWN Submitted by: Ambry Genetics
- hereditary breast carcinomaInheritance: AD Classification: NO_KNOWN Submitted by: ClinGen
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ACMG classification
Our verdict: Pathogenic. The variant received 16 ACMG points.
Transcripts
RefSeq
| Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | MANE | Protein | UniProt |
|---|---|---|---|---|---|---|---|---|
| MLH1 | NM_000249.4 | c.440G>A | p.Gly147Glu | missense_variant | Exon 5 of 19 | ENST00000231790.8 | NP_000240.1 |
Ensembl
| Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | TSL | MANE | Protein | Appris | UniProt |
|---|---|---|---|---|---|---|---|---|---|---|
| MLH1 | ENST00000231790.8 | c.440G>A | p.Gly147Glu | missense_variant | Exon 5 of 19 | 1 | NM_000249.4 | ENSP00000231790.3 |
Frequencies
GnomAD3 genomes Cov.: 32
GnomAD4 exome Cov.: 29
GnomAD4 genome Cov.: 32
ClinVar
Submissions by phenotype
Hereditary cancer-predisposing syndrome Pathogenic:1Uncertain:1
PM2_Supporting, PP1, PP3_Moderate c.440G>A, located in exon 5 of the MLH1 gene, is predicted to result in the substitution of Glycine by Glutamic acid at codon 147, p.(Gly147Glu). It is not present in the population database gnomAD v4.1.0 (PM2_Supporting). The SpliceAI algorithm predicts no significant impact on splicing. Computational tools predict a deleterious effect of the variant on protein function (MAPP+PolyPhen-2 prior probability for pathogenicity: 0.96) (PP3_Moderate). To our knowledge, well-stablished functional studies have not been reported for this variant. It has been reported in 1 CRC MSI-H tumor using a standard panel of 5-10 markers and in 1 CRC with loss of MMR protein expression consistent with the variant location. However, in both cases methylation study is not available (InSiGHT database). The variant co-segregates in two families with a total segregation Odds Pathogenicity of 3.17 (InSiGHT database) (PP1). It has been reported as a likely pathogenic variant in ClinVar, InSiGHT and LOVD databases. Based on the currently available information, c.440G>A is classified as an uncertain significance variant according to ClinGen-MLH1 Guidelines version 1.
The p.G147E variant (also known as c.440G>A), located in coding exon 5 of the MLH1 gene, results from a G to A substitution at nucleotide position 440. The glycine at codon 147 is replaced by glutamic acid, an amino acid with similar properties. This amino acid position is highly conserved in available vertebrate species. This variant has been identified as germline in an individual meeting Amsterdam criteria with MSI-H colorectal cancer also demonstrating loss of PMS2 and weak MLH1 staining by IHC. Somatic copy-neutral loss of heterozygosity (CN-LOH) of MLH1 was also identified in this individual's tumor (Ambry internal data). This variant was not reported in population-based cohorts in the Genome Aggregation Database (gnomAD). This alteration has been classified as likely pathogenic using the following lines of evidence: in silico prediction models, segregation with disease, clinical phenotype including tumor characteristics, mutation co-occurrence, and functional studies (Thompson BA et al. Hum. Mutat. 2013 Jan;34:200-9; Thompson BA et al. Nat. Genet. 2014 Feb;46:107-15; available at [www.insight-group.org/variants/classifications/]). In addition, this alteration is predicted to be deleterious by in silico analysis. Based on the majority of available evidence to date, this variant is likely to be pathogenic.
Lynch syndrome Pathogenic:1
Multifactorial likelihood analysis posterior probability > 0.95 (0.966)
Hereditary nonpolyposis colorectal neoplasms Pathogenic:1
In summary, the currently available evidence indicates that the variant is pathogenic, but additional data are needed to prove that conclusively. Therefore, this variant has been classified as Likely Pathogenic. Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is expected to disrupt MLH1 protein function. ClinVar contains an entry for this variant (Variation ID: 574220). This missense change has been observed in individuals with Lynch syndrome (Invitae; external communication). This variant is not present in population databases (gnomAD no frequency). This sequence change replaces glycine, which is neutral and non-polar, with glutamic acid, which is acidic and polar, at codon 147 of the MLH1 protein (p.Gly147Glu).
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at