Variant chr3-36996706-C-G details in Genebe, Genetics Data Aggregator

Variant summary

Our verdict is Likely pathogenic. Variant got 6 ACMG points: 6P and 0B. PM2PP3_Strong

The NM_001167617.3(MLH1):c.-86C>G variant causes a 5 prime UTR premature start codon gain change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000274 in 1,458,640 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 (★★).

Frequency

Genomes: not found (cov: 32)

Exomes 𝑓: 0.0000027 ( 0 hom. )

Consequence

MLH1
NM_001167617.3 5_prime_UTR_premature_start_codon_gain

Scores

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:8

Conservation

PhyloP100: 0.261

Variant links:

Genes affected

MLH1 (HGNC:7127): (mutL homolog 1) The protein encoded by this gene can heterodimerize with mismatch repair endonuclease PMS2 to form MutL alpha, part of the DNA mismatch repair system. When MutL alpha is bound by MutS beta and some accessory proteins, the PMS2 subunit of MutL alpha introduces a single-strand break near DNA mismatches, providing an entry point for exonuclease degradation. The encoded protein is also involved in DNA damage signaling and can heterodimerize with DNA mismatch repair protein MLH3 to form MutL gamma, which is involved in meiosis. This gene was identified as a locus frequently mutated in hereditary nonpolyposis colon cancer (HNPCC). [provided by RefSeq, Aug 2017]

MLH1 links:

MLH1 (HGNC:):

MLH1 links:

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ACMG classification

Classification made for transcript

Verdict is Likely_pathogenic. Variant got 6 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

PP3

MetaRNN computational evidence supports a deleterious effect, 0.977

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
MLH1	NM_000249.4 linkuse as main transcript	c.204C>G	p.Ile68Met	missense_variant	2/19	ENST00000231790.8	NP_000240.1	P40692-1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
MLH1	ENST00000231790.8 linkuse as main transcript	c.204C>G	p.Ile68Met	missense_variant	2/19	1	NM_000249.4	ENSP00000231790.3		P40692-1

Frequencies

GnomAD3 genomes

Cov.:

GnomAD3 exomes

AF:

0.00000398

AC:

AN:

251396

Hom.:

AF XY:

0.00000736

AC XY:

AN XY:

135872

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad SAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00000880

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.00000274

AC:

AN:

1458640

Hom.:

Cov.:

AF XY:

0.00000551

AC XY:

AN XY:

725930

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.00

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.00000361

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

Cov.:

ExAC

AF:

0.00000824

AC:

EpiCase

AF:

0.000109

EpiControl

AF:

0.0000593

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:8

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Lynch syndrome

Uncertain:2

Uncertain significance, criteria provided, single submitter	clinical testing	Mendelics	Jul 02, 2018	- -
Uncertain significance, criteria provided, single submitter	clinical testing	All of Us Research Program, National Institutes of Health	Apr 03, 2023	This missense variant replaces isoleucine with methionine at codon 68 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 colorectal cancer but without the clinical features of Lynch syndrome (PMID: 25435955). This variant has been identified in 1/251396 chromosomes in the general population by the Genome Aggregation Database (gnomAD). Different variants affecting the same codon, c.203T>G (p.Ile68Ser) and c.203T>A (p.Ile68Asn), are considered to be disease-causing (ClinVar variation ID: 820585, 90008), suggesting that this position is important for the protein function. 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. -

not provided

Uncertain:2

Uncertain significance, criteria provided, single submitter	clinical testing	Quest Diagnostics Nichols Institute San Juan Capistrano	Nov 02, 2024	The MLH1 c.204C>G (p.Ile68Met) variant has been reported in the published literature in individuals with rectal cancer (PMID: 25435955 (2015)) and thyroid cancer (PMID: 25576899 (2015)). At least one other missense variant at this codon (MLH1 c.203T>A (p.Ile68Asn), Quest internal data, ClinVar Variation ID: 90008) is considered to be pathogenic or likely pathogenic, suggesting this variant may also cause disease. The frequency of this variant in the general population, 0.000004 (1/251396 chromosomes (Genome Aggregation Database, http://gnomad.broadinstitute.org)), is uninformative in the assessment of its pathogenicity. Analysis of this variant using bioinformatics tools for the prediction of the effect of amino acid changes on protein structure and function yielded conflicting predictions that this variant is benign or damaging. Based on the available information, we are unable to determine the clinical significance of this variant. -
Uncertain significance, criteria provided, single submitter	clinical testing	GeneDx	Dec 01, 2022	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; Observed in individuals with colorectal cancer (Vodicka et al., 2015); This variant is associated with the following publications: (PMID: 25576899, 22753075, 16083711, 21120944, 25435955) -

Hereditary cancer-predisposing syndrome

Uncertain:2

Uncertain significance, criteria provided, single submitter	clinical testing	Color Diagnostics, LLC DBA Color Health	Mar 17, 2023	This missense variant replaces isoleucine with methionine at codon 68 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 colorectal cancer but without the clinical features of Lynch syndrome (PMID: 25435955). This variant has been identified in 1/251396 chromosomes in the general population by the Genome Aggregation Database (gnomAD). Different variants affecting the same codon, c.203T>G (p.Ile68Ser) and c.203T>A (p.Ile68Asn), are considered to be disease-causing (ClinVar variation ID: 820585, 90008), suggesting that this position is important for the protein function. 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. -
Uncertain significance, criteria provided, single submitter	clinical testing	Ambry Genetics	May 01, 2023	The p.I68M variant (also known as c.204C>G), located in coding exon 2 of the MLH1 gene, results from a C to G substitution at nucleotide position 204. The isoleucine at codon 68 is replaced by methionine, an amino acid with highly similar properties. This alteration has been reported in both germline and tumor DNA of a 59 year old female with rectal cancer; however, the expression of MLH1 was not altered in the tumor. Authors also report that the amino acid residue 68 is located within the enzymatic core on the MLH1 protein which interacts with ATP; they conclude that a substitution by methionine may decrease MLH1 activity (Vodicka P et al, Oncol Lett 2015 Jan; 9(1):183-186). 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. -

Colorectal cancer, hereditary nonpolyposis, type 2

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Baylor Genetics

Feb 12, 2024

- -

Hereditary nonpolyposis colorectal neoplasms

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Jan 21, 2024

This sequence change replaces isoleucine, which is neutral and non-polar, with methionine, which is neutral and non-polar, at codon 68 of the MLH1 protein (p.Ile68Met). This variant is present in population databases (rs780141938, gnomAD 0.0009%). This missense change has been observed in individual(s) with colorectal cancer (PMID: 25435955). ClinVar contains an entry for this variant (Variation ID: 486852). 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) has been performed at Invitae for this missense variant, however the output from this modeling did not meet the statistical confidence thresholds required to predict the impact of this variant on MLH1 protein function. This variant disrupts the p.Ile68 amino acid residue in MLH1. Other variant(s) that disrupt this residue have been determined to be pathogenic (PMID: 10082584, 11304573, 11555625, 12810663, 14961575, 17510385, 24362816). This suggests that this residue is clinically significant, and that variants that disrupt this residue are likely to be disease-causing. 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. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Pathogenic

0.72

BayesDel_addAF

Pathogenic

0.39

BayesDel_noAF

Pathogenic

0.32

CADD

Uncertain

DANN

Uncertain

1.0

DEOGEN2

Uncertain

0.79

Eigen

Benign

0.11

Eigen_PC

Benign

0.14

FATHMM_MKL

Uncertain

0.85

LIST_S2

Pathogenic

0.99

M_CAP

Pathogenic

0.42

MetaRNN

Pathogenic

0.98

MetaSVM

Benign

-0.78

MutationAssessor

Benign

2.0

PrimateAI

Uncertain

0.79

PROVEAN

Uncertain

-2.7

REVEL

Pathogenic

0.81

Sift

Pathogenic

0.0

Sift4G

Pathogenic

0.0

Polyphen

1.0

Vest4

0.81

MutPred

0.90

Loss of catalytic residue at L73 (P = 0.039);

MVP

0.96

MPC

0.41

ClinPred

0.96

GERP RS

3.1

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

1.1

Varity_R

0.96

gMVP

0.84

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.0

Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

LitVar

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over