3-36993575-C-T
Variant summary
Our verdict is Uncertain significance. The variant received 4 ACMG points: 4P and 0B. PM2PP3_Moderate
The NM_000249.4(MLH1):c.28C>T(p.Arg10Trp) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000137 in 1,461,884 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R10L) 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: Uncertain_significance. The variant received 4 ACMG points.
Transcripts
RefSeq
Ensembl
Frequencies
GnomAD3 genomes  Cov.: 33 
GnomAD2 exomes  AF:  0.00000398  AC: 1AN: 251438 AF XY:  0.00000736   show subpopulations 
GnomAD4 exome  AF:  0.00000137  AC: 2AN: 1461884Hom.:  0  Cov.: 31 AF XY:  0.00000275  AC XY: 2AN XY: 727244 show subpopulations 
Age Distribution
GnomAD4 genome  Cov.: 33 
ClinVar
Submissions by phenotype
Hereditary cancer-predisposing syndrome    Uncertain:3 
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This missense variant replaces arginine with tryptophan at codon 10 of the MLH1 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 reported in an individual affected with breast cancer (PMID: 29335925). This variant has also been identified in 1/251438 chromosomes in the general population by the Genome Aggregation Database (gnomAD). The available evidence is insufficient to determine the role of this variant in disease conclusively. Therefore, this variant is classified as a Variant of Uncertain Significance. -
The p.R10W variant (also known as c.28C>T), located in coding exon 1 of the MLH1 gene, results from a C to T substitution at nucleotide position 28. The arginine at codon 10 is replaced by tryptophan, an amino acid with dissimilar properties. This alteration has been reported in a Greek male breast cancer patient (Fostira F et al. Breast Cancer Res. Treat., 2018 May;169:105-113). This amino acid position is highly conserved in available vertebrate species. In addition, this alteration is predicted to be deleterious by in silico analysis. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -
not specified    Uncertain:1 
Variant summary: MLH1 c.28C>T (p.Arg10Trp) results in a non-conservative amino acid change located in the DNA mismatch repair protein family, N-terminal domain (IPR002099) of the encoded protein sequence. Five of five in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 4e-06 in 251438 control chromosomes. The available data on variant occurrences in the general population are insufficient to allow any conclusion about variant significance. c.28C>T has been reported in the literature as a VUS in settings of multigene panel testing in one individual from a cohort of 102 Greek male breast cancer (MBC) patients (example, Fostira_2018). These report(s) do not provide unequivocal conclusions about association of the variant with Lynch Syndrome. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. Three 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 uncertain significance. Based on the evidence outlined above, the variant was classified as uncertain significance. -
Colorectal cancer, hereditary nonpolyposis, type 2    Uncertain:1 
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Hereditary nonpolyposis colorectal neoplasms    Uncertain:1 
This missense change has been observed in individual(s) with breast cancer (PMID: 29335925). In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. Algorithms developed to predict the effect of missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be disruptive. ClinVar contains an entry for this variant (Variation ID: 489898). This variant is present in population databases (no rsID available, gnomAD 0.003%). This sequence change replaces arginine, which is basic and polar, with tryptophan, which is neutral and slightly polar, at codon 10 of the MLH1 protein (p.Arg10Trp). -
Computational scores
Source: 
Splicing
 Find out detailed SpliceAI scores and Pangolin per-transcript scores at