rs63751448
Variant summary
Our verdict is Likely pathogenic. Variant got 6 ACMG points: 6P and 0B. PM1PM5PP3_Moderate
The NM_000249.4(MLH1):c.794G>A(p.Arg265His) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000725 in 1,613,572 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 12/21 in silico tools predict a damaging outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R265C) has been classified as Pathogenic.
Frequency
Consequence
NM_000249.4 missense
Scores
Clinical Significance
Conservation
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ACMG classification
Verdict is Likely_pathogenic. Variant got 6 ACMG points.
Transcripts
RefSeq
Gene | Transcript | HGVSc | HGVSp | Effect | #exon/exons | MANE | UniProt |
---|---|---|---|---|---|---|---|
MLH1 | NM_000249.4 | c.794G>A | p.Arg265His | missense_variant | 10/19 | ENST00000231790.8 |
Ensembl
Gene | Transcript | HGVSc | HGVSp | Effect | #exon/exons | TSL | MANE | Appris | UniProt |
---|---|---|---|---|---|---|---|---|---|
MLH1 | ENST00000231790.8 | c.794G>A | p.Arg265His | missense_variant | 10/19 | 1 | NM_000249.4 | P1 |
Frequencies
GnomAD3 genomes ? AF: 0.0000461 AC: 7AN: 151988Hom.: 0 Cov.: 32
GnomAD3 exomes AF: 0.0000477 AC: 12AN: 251462Hom.: 0 AF XY: 0.0000589 AC XY: 8AN XY: 135900
GnomAD4 exome AF: 0.0000753 AC: 110AN: 1461584Hom.: 0 Cov.: 31 AF XY: 0.0000660 AC XY: 48AN XY: 727114
GnomAD4 genome ? AF: 0.0000461 AC: 7AN: 151988Hom.: 0 Cov.: 32 AF XY: 0.0000539 AC XY: 4AN XY: 74238
ClinVar
Submissions by phenotype
Hereditary cancer-predisposing syndrome Uncertain:2Benign:2
Likely benign, criteria provided, single submitter | clinical testing | Ambry Genetics | May 21, 2020 | This alteration is classified as likely benign based on a combination of the following: seen in unaffected individuals, population frequency, intact protein function, lack of segregation with disease, co-occurrence, RNA analysis, in silico models, amino acid conservation, lack of disease association in case-control studies, and/or the mechanism of disease or impacted region is inconsistent with a known cause of pathogenicity. - |
Uncertain significance, criteria provided, single submitter | clinical testing | Institute for Biomarker Research, Medical Diagnostic Laboratories, L.L.C. | Nov 06, 2023 | - - |
Uncertain significance, no assertion criteria provided | clinical testing | True Health Diagnostics | Nov 01, 2017 | - - |
Likely benign, criteria provided, single submitter | clinical testing | Color Diagnostics, LLC DBA Color Health | Jun 14, 2016 | - - |
not specified Uncertain:3
Uncertain significance, criteria provided, single submitter | clinical testing | Department of Pathology and Laboratory Medicine, Sinai Health System | Dec 05, 2014 | - - |
Uncertain significance, criteria provided, single submitter | clinical testing | Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine | Jun 16, 2016 | Variant identified in a genome or exome case(s) and assessed due to predicted null impact of the variant or pathogenic assertions in the literature or databases. Disclaimer: This variant has not undergone full assessment. The following are preliminary notes: 13 papers in HGMD, however several of these call pathogenicity into question. ClinVar: 3 VUS (including expert panel - no new evidence since this classification), 1 LB - |
Uncertain significance, criteria provided, single submitter | clinical testing | Center for Genomic Medicine, Rigshospitalet, Copenhagen University Hospital | Aug 15, 2023 | - - |
not provided Uncertain:3
Uncertain significance, criteria provided, single submitter | clinical testing | GeneDx | Jun 06, 2023 | Published functional studies are conflicting: normal protein expression, but also partial exon skipping and inconsistent mismatch repair function (Shimodaira et al., 1998; Ellison et al., 2001; Kondo et al., 2003; Takahashi et al., 2007; Tournier et al., 2008; Hinrichsen et al., 2013; Soukarieh et al., 2016); Observed in individuals with MLH1-related cancers, occurring on the same allele (in cis) with a truncating MLH1 variant in one family (Viel et al., 1997; Tournier et al., 2008); 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: 22736432, 20176959, 23403630, 25525159, 28492532, 10573010, 31697235, 21239990, 12810663, 17510385, 11781295, 17210669, 17594722, 9697702, 25871441, 18205192, 16830052, 17192056, 23741719, 18373977, 26761715, 11555625, 18561205, 8993976, 9827806, 28668638, 29520894, 19339519, 22290698, 32170000, 33326660, 35731023, 22753075, 31332305, 30623411, 32133419, 18383312, 37240284) - |
Uncertain significance, criteria provided, single submitter | clinical testing | CeGaT Center for Human Genetics Tuebingen | Dec 01, 2021 | - - |
Uncertain significance, criteria provided, single submitter | clinical testing | Quest Diagnostics Nichols Institute San Juan Capistrano | Dec 21, 2018 | - - |
Colorectal cancer, hereditary nonpolyposis, type 2 Uncertain:1Benign:1
Likely benign, criteria provided, single submitter | clinical testing | Myriad Genetics, Inc. | Mar 14, 2023 | This variant is considered likely benign. This variant is strongly associated with less severe personal and family histories of cancer, typical for individuals without pathogenic variants in this gene [PMID: 25085752]. - |
Uncertain significance, criteria provided, single submitter | clinical testing | Counsyl | Nov 24, 2015 | - - |
Hereditary nonpolyposis colon cancer Uncertain:1
Uncertain significance, criteria provided, single submitter | clinical testing | Cancer Variant Interpretation Group UK, Institute of Cancer Research, London | Mar 12, 2019 | Data included in classification: Predicted deleterious on SIFT, Polyphen, Align GVGD; Polyphen HumVar (PP3_sup). Three other variants at this position p.(Arg265Ser) and p.(Arg265Pro) and p.(Arg265Cys) all classed as likely pathogenic/pathogenic by InSiGHT. All of these have sufficient additional evidence (RNA studies / segregation / multiple cases / MSI / IHC) to support the classifications (PM5_mod). Additional information (not included in classification): 2 UK families. UK Family 1: Proband: Breast cancer at 42, Mucinous ovarian cancer. IHC: normal. Mother: Colorectal cancer at 74. IHC: normal. UK Family 2: Proband: Right sided bowel cancer age 51, Loss of MSH6 and MSH2 on IHC and MSI-High. Proband also had pathogenic MSH2. Literature (as per INSIGHT): 2 Italian families: In both variant is in cis with frameshift variant (Viel et al 1997, Genuardi et al 1999, Pastrello et al, 2011). 1 French family: Variant in trans with pathogenic MLH1 variant (Tournier et al 2008). Controls: The variant was observed 8/56,871 GNOMAD NFE controls and 4/68,860 individuals in the remainder of the GNOMAD population. Splicing data: Splicing predictions equivocal. Splicing functional data conflicting: (some functional affect on splicing: PMID 17510385, 18561205, 25525159, no effect/minimal effect PMID 9697702, 12810663, 23403630). Other classifications: Multiple classifications of VUS in ClinVar. - |
Hereditary nonpolyposis colorectal neoplasms Uncertain:1
Uncertain significance, criteria provided, single submitter | clinical testing | Invitae | Jan 31, 2024 | This sequence change replaces arginine, which is basic and polar, with histidine, which is basic and polar, at codon 265 of the MLH1 protein (p.Arg265His). This variant is present in population databases (rs63751448, gnomAD 0.007%). This missense change has been observed in individual(s) with clinical features of Lynch syndrome (PMID: 8993976, 18561205; Invitae). ClinVar contains an entry for this variant (Variation ID: 90381). 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 with a positive predictive value of 95%. Experimental studies have shown that this missense change does not substantially affect MLH1 function (PMID: 9697702, 11781295, 12810663, 17510385, 23403630). Studies have shown this missense change is associated with skipping of exon 10 and/or skipping of exons 10-11, but one or more of the resulting mRNA isoform(s) may be naturally occurring (PMID: 30623411, 31332305, 32133419; Invitae). 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. - |
Hereditary breast ovarian cancer syndrome Uncertain:1
Uncertain significance, criteria provided, single submitter | research | Molecular Oncology Research Center, Barretos Cancer Hospital | Jan 25, 2024 | - - |
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at