rs41295284

Variant summary

Our verdict is Likely benign. Variant got -4 ACMG points: 4P and 8B. PM1PP3_ModerateBP6_Very_Strong

The NM_000249.4(MLH1):​c.1820T>A​(p.Leu607His) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000191 in 1,614,182 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 Likely benign (★★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. L607I) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.00016 ( 0 hom., cov: 31)
Exomes 𝑓: 0.00019 ( 0 hom. )

Consequence

MLH1
NM_000249.4 missense

Scores

14
4
1

Clinical Significance

Likely benign reviewed by expert panel U:2B:15

Conservation

PhyloP100: 7.81
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 -4 ACMG points.

PM1
In a hotspot region, there are 3 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 2 benign, 16 uncertain in NM_000249.4
PP3
MetaRNN computational evidence supports a deleterious effect, 0.843
BP6
Variant 3-37047607-T-A is Benign according to our data. Variant chr3-37047607-T-A is described in ClinVar as [Likely_benign]. Clinvar id is 89895.Status of the report is reviewed_by_expert_panel, 3 stars. Variant chr3-37047607-T-A is described in Lovd as [Likely_benign]. Variant chr3-37047607-T-A is described in Lovd as [Benign]. Variant chr3-37047607-T-A is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect #exon/exons MANE UniProt
MLH1NM_000249.4 linkuse as main transcriptc.1820T>A p.Leu607His missense_variant 16/19 ENST00000231790.8

Ensembl

Gene Transcript HGVSc HGVSp Effect #exon/exons TSL MANE Appris UniProt
MLH1ENST00000231790.8 linkuse as main transcriptc.1820T>A p.Leu607His missense_variant 16/191 NM_000249.4 P1P40692-1

Frequencies

GnomAD3 genomes
AF:
0.000158
AC:
24
AN:
152188
Hom.:
0
Cov.:
31
show subpopulations
Gnomad AFR
AF:
0.0000965
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.000131
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:
0.000265
Gnomad OTH
AF:
0.00
GnomAD3 exomes
AF:
0.000187
AC:
47
AN:
251378
Hom.:
0
AF XY:
0.000155
AC XY:
21
AN XY:
135848
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.000347
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:
0.000290
Gnomad OTH exome
AF:
0.000326
GnomAD4 exome
AF:
0.000194
AC:
284
AN:
1461876
Hom.:
0
Cov.:
31
AF XY:
0.000205
AC XY:
149
AN XY:
727242
show subpopulations
Gnomad4 AFR exome
AF:
0.00
Gnomad4 AMR exome
AF:
0.000335
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:
0.000230
Gnomad4 OTH exome
AF:
0.000215
GnomAD4 genome
AF:
0.000158
AC:
24
AN:
152306
Hom.:
0
Cov.:
31
AF XY:
0.000175
AC XY:
13
AN XY:
74474
show subpopulations
Gnomad4 AFR
AF:
0.0000962
Gnomad4 AMR
AF:
0.000131
Gnomad4 ASJ
AF:
0.00
Gnomad4 EAS
AF:
0.00
Gnomad4 SAS
AF:
0.00
Gnomad4 FIN
AF:
0.00
Gnomad4 NFE
AF:
0.000265
Gnomad4 OTH
AF:
0.00
Alfa
AF:
0.000154
Hom.:
0
Bravo
AF:
0.000113
TwinsUK
AF:
0.000270
AC:
1
ALSPAC
AF:
0.000259
AC:
1
ESP6500AA
AF:
0.000227
AC:
1
ESP6500EA
AF:
0.000581
AC:
5
ExAC
AF:
0.000198
AC:
24
EpiCase
AF:
0.000164
EpiControl
AF:
0.000356

ClinVar

Significance: Likely benign
Submissions summary: Uncertain:2Benign:15
Revision: reviewed by expert panel
LINK: link

Submissions by phenotype

not specified Uncertain:1Benign:4
Likely benign, criteria provided, single submitterclinical testingLaboratory for Molecular Medicine, Mass General Brigham Personalized MedicineOct 13, 2016Variant 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: Variant reported in 10 papers with functional data supporting non-pathogenic. Max MAF in ExAC is 0.04%. Classified by InSiGHT as Likely Benign (3 stars in ClinVar). -
Uncertain significance, no assertion criteria providedclinical testingMayo Clinic Laboratories, Mayo Clinic-- -
Benign, criteria provided, single submitterclinical testingWomen's Health and Genetics/Laboratory Corporation of America, LabCorpSep 27, 2021Variant summary: MLH1 c.1820T>A (p.Leu607His) results in a non-conservative amino acid change located in the DNA mismatch repair protein Mlh1, C-terminal domain 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 0.00018 in 254496 control chromosomes. This frequency is not significantly higher than expected for a pathogenic variant in MLH1 causing Hereditary Nonpolyposis Colorectal Cancer (0.00018 vs 0.00071), allowing no conclusion about variant significance. c.1820T>A has been reported in the literature in individuals affected with microsatellite stable (MSS) colorectal cancer, Lynch Syndrome or Lynch-syndrome associated cancers (e.g. Fidalgo_2000, Cravo_2002, Barnetson_2008, Valentin_2011, Castillejo_2014 ), including a family showing lack of co-segregation (Perez-Cabornero 2013). A recent study reporting tumour characteristic likelihood ratio (TCLR) for this variant, classified it as likely benign (Li_2020). The variant has been functionally characterized and shown to have no effect on splicing (Tournier 2008, Borras 2012) and MMR activity (Takahashi 2007, Houlleberghs_2020). One study (Xie 2010) indicated that the variant affects FANCJ binding which could play a role in cancer and/or chemoresistance due to a delay in MMR signaling. However, the conclusions drawn from this study remain speculative and do not allow an estimation of the risk associated with this variant. Therefore, the clinical and functional data do not allow any conclusion about variant significance. At-least one co-occurrence with another pathogenic variant has been observed at our laboratory (BRCA2 c.4137_4141delGATTA, p.Ile1380Argfs*21), providing supporting evidence for a benign role. Multiple clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014 with conflicting assessments and a majority consensus towards a likely benign outcome. Based on the evidence outlined above, the variant was classified as benign. -
Likely benign, criteria provided, single submitterclinical testingGenetic Services Laboratory, University of ChicagoSep 09, 2020- -
Likely benign, criteria provided, single submitterclinical testingDepartment of Pathology and Laboratory Medicine, Sinai Health SystemDec 18, 2014- -
Hereditary cancer-predisposing syndrome Benign:3
Likely benign, criteria provided, single submitterclinical testingAmbry GeneticsSep 07, 2018This 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. -
Likely benign, criteria provided, single submitterclinical testingColor Diagnostics, LLC DBA Color HealthJan 01, 2022- -
Likely benign, criteria provided, single submittercurationSema4, Sema4Oct 26, 2020- -
Colorectal cancer, hereditary nonpolyposis, type 2 Uncertain:1Benign:1
Uncertain significance, criteria provided, single submitterclinical testingIllumina Laboratory Services, IlluminaApr 27, 2017This variant was observed as part of a predisposition screen in an ostensibly healthy population. A literature search was performed for the gene, cDNA change, and amino acid change (where applicable). Publications were found based on this search. However, the evidence from the literature, in combination with allele frequency data from public databases where available, was not sufficient to rule this variant in or out of causing disease. Therefore, this variant is classified as a variant of unknown significance. -
Likely benign, criteria provided, single submitterclinical testingMendelicsMay 28, 2019- -
not provided Benign:2
Likely benign, criteria provided, single submitterclinical testingGeneDxNov 16, 2020This variant is associated with the following publications: (PMID: 19389263, 17510385, 18561205, 20978114, 10713887, 11839723, 21681552, 23523604, 22949387, 18566915, 23588873, 22736432, 21056691, 18033691, 15365995, 11369138, 25871441, 20978117, 26637282, 23741719, 17192056, 24933000, 15222003, 26926912, 31784484) -
Likely benign, criteria provided, single submitterclinical testingQuest Diagnostics Nichols Institute San Juan CapistranoSep 26, 2022- -
Breast and/or ovarian cancer Benign:1
Likely benign, criteria provided, single submitterclinical testingCHEO Genetics Diagnostic Laboratory, Children's Hospital of Eastern OntarioJun 05, 2023- -
Muir-Torré syndrome;C1333991:Colorectal cancer, hereditary nonpolyposis, type 2;C5399763:Mismatch repair cancer syndrome 1 Benign:1
Likely benign, criteria provided, single submitterclinical testingFulgent Genetics, Fulgent GeneticsMar 15, 2022- -
Lynch syndrome Benign:1
Likely benign, reviewed by expert panelresearchInternational Society for Gastrointestinal Hereditary Tumours (InSiGHT)Sep 05, 2013Multifactorial likelihood analysis posterior probability 0.001-0.049 -
MLH1-related disorder Benign:1
Likely benign, no assertion criteria providedclinical testingPreventionGenetics, part of Exact SciencesOct 30, 2019This variant is classified as likely benign based on ACMG/AMP sequence variant interpretation guidelines (Richards et al. 2015 PMID: 25741868, with internal and published modifications). -
Hereditary nonpolyposis colorectal neoplasms Benign:1
Likely benign, criteria provided, single submitterclinical testingLabcorp Genetics (formerly Invitae), LabcorpJan 31, 2024- -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Pathogenic
0.98
BayesDel_addAF
Pathogenic
0.32
D
BayesDel_noAF
Pathogenic
0.52
CADD
Pathogenic
27
DANN
Uncertain
0.99
DEOGEN2
Pathogenic
0.91
D;.;.;.;.;.
Eigen
Uncertain
0.61
Eigen_PC
Uncertain
0.62
FATHMM_MKL
Pathogenic
0.97
D
LIST_S2
Uncertain
0.96
D;D;.;.;.;D
M_CAP
Pathogenic
0.69
D
MetaRNN
Pathogenic
0.84
D;D;D;D;D;D
MetaSVM
Pathogenic
0.98
D
MutationAssessor
Pathogenic
3.3
M;.;.;.;.;.
MutationTaster
Benign
1.0
D;D;D;D;D;D
PrimateAI
Pathogenic
0.84
D
PROVEAN
Pathogenic
-6.1
D;D;D;D;D;D
REVEL
Pathogenic
0.93
Sift
Pathogenic
0.0
D;D;D;D;D;D
Sift4G
Pathogenic
0.0010
D;D;D;D;D;D
Polyphen
1.0
D;.;.;.;.;.
Vest4
0.83
MVP
0.96
MPC
0.45
ClinPred
0.56
D
GERP RS
5.3
Varity_R
0.92
gMVP
0.83

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: rs41295284; hg19: chr3-37089098; COSMIC: COSV105856838; API