rs1553640212
Variant summary
Our verdict is Likely pathogenic. The variant received 8 ACMG points: 8P and 0B. PM1PM2PP3_Strong
The NM_000249.4(MLH1):c.236G>A(p.Arg79Lys) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000000687 in 1,455,870 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. R79T) 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: Likely_pathogenic. The variant received 8 ACMG points.
Transcripts
RefSeq
Ensembl
Frequencies
GnomAD3 genomes Cov.: 32
GnomAD2 exomes AF: 0.00000398 AC: 1AN: 251380 AF XY: 0.00 show subpopulations
GnomAD4 exome AF: 6.87e-7 AC: 1AN: 1455870Hom.: 0 Cov.: 29 AF XY: 0.00 AC XY: 0AN XY: 724764 show subpopulations ⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.
Age Distribution
GnomAD4 genome Cov.: 32
ClinVar
Submissions by phenotype
Hereditary cancer-predisposing syndrome Uncertain:2
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The p.R79K variant (also known as c.236G>A), located in coding exon 3 of the MLH1 gene, results from a G to A substitution at nucleotide position 236. The arginine at codon 79 is replaced by lysine, an amino acid with highly similar properties. This alteration was identified in an individual diagnosed with glioblastoma (Kara B et al. Turk J Pediatr, 2022;64:1106-1116). 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. -
Hereditary nonpolyposis colorectal neoplasms Uncertain:1
This sequence change replaces arginine, which is basic and polar, with lysine, which is basic and polar, at codon 79 of the MLH1 protein (p.Arg79Lys). This variant is not present in population databases (gnomAD no frequency). 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: 483597). This variant has not been reported in the literature in individuals affected with MLH1-related conditions. -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at