rs754554026

Variant summary

Our verdict is Likely benign. Variant got -2 ACMG points: 0P and 2B. BP4_Moderate

The NM_000249.4(MLH1):​c.1490G>A​(p.Arg497Gln) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000217 in 1,614,036 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 32)
Exomes 𝑓: 0.000023 ( 0 hom. )

Consequence

MLH1
NM_000249.4 missense

Scores

9
10

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:7B:2

Conservation

PhyloP100: 2.71
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]

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Likely_benign. Variant got -2 ACMG points.

BP4
Computational evidence support a benign effect (MetaRNN=0.24122486).

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
MLH1NM_000249.4 linkc.1490G>A p.Arg497Gln missense_variant Exon 13 of 19 ENST00000231790.8 NP_000240.1 P40692-1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
MLH1ENST00000231790.8 linkc.1490G>A p.Arg497Gln missense_variant Exon 13 of 19 1 NM_000249.4 ENSP00000231790.3 P40692-1

Frequencies

GnomAD3 genomes
AF:
0.00000657
AC:
1
AN:
152170
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.00
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.00
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.00
Gnomad SAS
AF:
0.00
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.0000147
Gnomad OTH
AF:
0.00
GnomAD3 exomes
AF:
0.0000278
AC:
7
AN:
251480
Hom.:
0
AF XY:
0.0000221
AC XY:
3
AN XY:
135908
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.0000578
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad SAS exome
AF:
0.000131
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00000879
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000233
AC:
34
AN:
1461866
Hom.:
0
Cov.:
32
AF XY:
0.0000220
AC XY:
16
AN XY:
727242
show subpopulations
Gnomad4 AFR exome
AF:
0.00
Gnomad4 AMR exome
AF:
0.0000447
Gnomad4 ASJ exome
AF:
0.00
Gnomad4 EAS exome
AF:
0.0000252
Gnomad4 SAS exome
AF:
0.0000927
Gnomad4 FIN exome
AF:
0.00
Gnomad4 NFE exome
AF:
0.0000189
Gnomad4 OTH exome
AF:
0.0000331
GnomAD4 genome
AF:
0.00000657
AC:
1
AN:
152170
Hom.:
0
Cov.:
32
AF XY:
0.0000134
AC XY:
1
AN XY:
74356
show subpopulations
Gnomad4 AFR
AF:
0.00
Gnomad4 AMR
AF:
0.00
Gnomad4 ASJ
AF:
0.00
Gnomad4 EAS
AF:
0.00
Gnomad4 SAS
AF:
0.00
Gnomad4 FIN
AF:
0.00
Gnomad4 NFE
AF:
0.0000147
Gnomad4 OTH
AF:
0.00
Bravo
AF:
0.00000756
ExAC
AF:
0.0000330
AC:
4
EpiCase
AF:
0.00
EpiControl
AF:
0.0000593

ClinVar

Significance: Conflicting classifications of pathogenicity
Submissions summary: Uncertain:7Benign:2
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

not provided Uncertain:2
Oct 31, 2019
GeneDx
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

In silico analysis, which includes protein predictors and evolutionary conservation, supports a deleterious effect; Has not been previously published as a germline pathogenic or benign variant to our knowledge; This variant is associated with the following publications: (PMID: 29596542, 22608206) -

Jul 03, 2024
Quest Diagnostics Nichols Institute San Juan Capistrano
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

The MLH1 c.1490G>A (p.Arg497Gln) variant has been reported in the published literature in an individual with colorectal cancer (PMID: 32658311 (2021)), and an individual referred for hereditary cancer testing (PMID: 34359559 (2021)). The frequency of this variant in the general population, 0.00013 (4/30616 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 predictions that this variant is benign. Based on the available information, we are unable to determine the clinical significance of this variant. -

Hereditary cancer-predisposing syndrome Uncertain:2
Nov 16, 2022
Color Diagnostics, LLC DBA Color Health
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

This missense variant replaces arginine with glutamine at codon 497 of the MLH1 protein. Computational prediction suggests that this variant may not impact protein structure and function (internally defined REVEL score threshold <= 0.5, PMID: 27666373). To our knowledge, functional studies have not been reported for this variant. This variant has not been reported in individuals affected with MLH1-related disorders in the literature. This variant has been identified in 7/251480 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. -

Mar 08, 2024
Ambry Genetics
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

The p.R497Q variant (also known as c.1490G>A), located in coding exon 13 of the MLH1 gene, results from a G to A substitution at nucleotide position 1490. The arginine at codon 497 is replaced by glutamine, an amino acid with highly similar properties. This alteration was seen in 0/732 breast cancer patients, 1/189 colorectal cancer patients and 0/490 cancer-free elderly controls in a Turkish population (Akcay IM et al. Int J Cancer, 2021 Jan;148:285-295). This amino acid position is well conserved in available vertebrate species. In addition, the in silico prediction for this alteration is inconclusive. Based on the available evidence, the clinical significance of this alteration remains unclear. -

Colorectal cancer, hereditary nonpolyposis, type 2 Uncertain:1Benign:1
Mar 05, 2024
Baylor Genetics
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

Nov 22, 2024
Myriad Genetics, Inc.
Significance: Likely benign
Review Status: criteria provided, single submitter
Collection Method: clinical testing

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: 27363726]. -

not specified Uncertain:1
Sep 03, 2023
Women's Health and Genetics/Laboratory Corporation of America, LabCorp
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

Variant summary: MLH1 c.1490G>A (p.Arg497Gln) results in a conservative amino acid change in the encoded protein sequence. Five of five in-silico tools predict a benign effect of the variant on protein function. The variant allele was found at a frequency of 2.8e-05 in 251480 control chromosomes. The available data on variant occurrences in the general population are insufficient to allow any conclusion about variant significance. To our knowledge, no occurrence of c.1490G>A in individuals affected with Hereditary Nonpolyposis Colorectal Cancer/Lynch syndrome and no experimental evidence demonstrating its impact on protein function have been reported. Four submitters have cited clinical-significance assessments for this variant to ClinVar after 2014 (VUS, n=4; LB, n=1). Based on the evidence outlined above, the variant was classified as uncertain significance. -

Lynch syndrome Uncertain:1
May 16, 2023
All of Us Research Program, National Institutes of Health
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

This missense variant replaces arginine with glutamine at codon 497 of the MLH1 protein. Computational prediction suggests that this variant may not impact protein structure and function (internally defined REVEL score threshold <= 0.5, PMID: 27666373). Splice site prediction tools suggest that this variant may not impact RNA splicing. To our knowledge, functional studies have not been performed for this variant. This variant has been reported in an individual suspected of having hereditary breast/ovarian cancer (PMID: 34359559). This variant has been identified in 7/251480 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. -

Hereditary nonpolyposis colorectal neoplasms Benign:1
Dec 16, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance: Likely benign
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.10
BayesDel_addAF
Uncertain
0.029
T
BayesDel_noAF
Uncertain
0.040
CADD
Uncertain
24
DANN
Uncertain
1.0
DEOGEN2
Benign
0.34
T;.;.;.;.;.;T;T
Eigen
Uncertain
0.26
Eigen_PC
Uncertain
0.38
FATHMM_MKL
Uncertain
0.78
D
LIST_S2
Uncertain
0.94
D;D;.;.;.;D;D;D
M_CAP
Benign
0.049
D
MetaRNN
Benign
0.24
T;T;T;T;T;T;T;T
MetaSVM
Uncertain
-0.048
T
MutationAssessor
Benign
1.9
L;.;.;.;.;.;.;.
PrimateAI
Benign
0.44
T
PROVEAN
Benign
-1.1
N;N;N;N;N;N;D;N
REVEL
Uncertain
0.39
Sift
Benign
0.076
T;T;T;T;T;T;D;T
Sift4G
Benign
0.18
T;T;T;T;T;T;T;T
Polyphen
0.15
B;.;.;.;.;.;.;.
Vest4
0.52
MutPred
0.35
Loss of helix (P = 0.0093);.;.;.;.;.;.;.;
MVP
0.94
MPC
0.077
ClinPred
0.15
T
GERP RS
5.9
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.1
Varity_R
0.13
gMVP
0.27

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.

Other links and lift over

dbSNP: rs754554026; hg19: chr3-37070355; COSMIC: COSV105856824; COSMIC: COSV105856824; API