NM_001040108.2:c.2224C>G

Variant summary

Our verdict is Uncertain significance. The variant received 0 ACMG points: 2P and 2B. PM2BP4_Moderate

The NM_001040108.2(MLH3):​c.2224C>G​(p.Arg742Gly) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000124 in 1,613,780 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 16/22 in silico tools predict a benign 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. R742C) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 33)
Exomes 𝑓: 6.8e-7 ( 0 hom. )

Consequence

MLH3
NM_001040108.2 missense

Scores

19

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:2

Conservation

PhyloP100: 0.934

Publications

0 publications found
Variant links:
Genes affected
MLH3 (HGNC:7128): (mutL homolog 3) This gene is a member of the MutL-homolog (MLH) family of DNA mismatch repair (MMR) genes. MLH genes are implicated in maintaining genomic integrity during DNA replication and after meiotic recombination. The protein encoded by this gene functions as a heterodimer with other family members. Somatic mutations in this gene frequently occur in tumors exhibiting microsatellite instability, and germline mutations have been linked to hereditary nonpolyposis colorectal cancer type 7 (HNPCC7). Several alternatively spliced transcript variants have been identified, but the full-length nature of only two transcript variants has been determined. [provided by RefSeq, Jul 2008]
MLH3 Gene-Disease associations (from GenCC):
  • colorectal cancer, hereditary nonpolyposis, type 7
    Inheritance: AD, AR Classification: MODERATE, LIMITED Submitted by: Ambry Genetics, ClinGen, Laboratory for Molecular Medicine

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Uncertain_significance. The variant received 0 ACMG points.

PM2
Very rare variant in population databases, with high coverage;
BP4
Computational evidence support a benign effect (MetaRNN=0.1145117).

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
MLH3NM_001040108.2 linkc.2224C>G p.Arg742Gly missense_variant Exon 2 of 13 ENST00000355774.7 NP_001035197.1 Q9UHC1-1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
MLH3ENST00000355774.7 linkc.2224C>G p.Arg742Gly missense_variant Exon 2 of 13 5 NM_001040108.2 ENSP00000348020.2 Q9UHC1-1
MLH3ENST00000380968.6 linkc.2224C>G p.Arg742Gly missense_variant Exon 2 of 12 1 ENSP00000370355.3 Q9UHC1-2
MLH3ENST00000556257.5 linkc.2224C>G p.Arg742Gly missense_variant Exon 2 of 7 5 ENSP00000451540.1 G3V419
MLH3ENST00000555671.1 linkn.-231C>G upstream_gene_variant 5

Frequencies

GnomAD3 genomes
AF:
0.00000658
AC:
1
AN:
152062
Hom.:
0
Cov.:
33
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
GnomAD4 exome
AF:
6.84e-7
AC:
1
AN:
1461718
Hom.:
0
Cov.:
35
AF XY:
0.00
AC XY:
0
AN XY:
727164
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33476
American (AMR)
AF:
0.00
AC:
0
AN:
44722
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26132
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39684
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86254
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53376
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
8.99e-7
AC:
1
AN:
1111914
Other (OTH)
AF:
0.00
AC:
0
AN:
60392
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.475
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance
GnomAD4 genome
AF:
0.00000658
AC:
1
AN:
152062
Hom.:
0
Cov.:
33
AF XY:
0.00
AC XY:
0
AN XY:
74260
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41394
American (AMR)
AF:
0.00
AC:
0
AN:
15260
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3468
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5196
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4824
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10586
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000147
AC:
1
AN:
68018
Other (OTH)
AF:
0.00
AC:
0
AN:
2088
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.575
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance
Alfa
AF:
0.00
Hom.:
0
Bravo
AF:
0.00000378

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:2
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

not specified Uncertain:1
Jun 18, 2023
Ambry Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The p.R742G variant (also known as c.2224C>G), located in coding exon 1 of the MLH3 gene, results from a C to G substitution at nucleotide position 2224. The arginine at codon 742 is replaced by glycine, an amino acid with dissimilar properties. This amino acid position is conserved. In addition, this alteration is predicted to be tolerated 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 7 Uncertain:1
May 19, 2022
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

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 tolerated. This variant has not been reported in the literature in individuals affected with MLH3-related conditions. This variant is not present in population databases (gnomAD no frequency). This sequence change replaces arginine, which is basic and polar, with glycine, which is neutral and non-polar, at codon 742 of the MLH3 protein (p.Arg742Gly). -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.11
BayesDel_addAF
Benign
-0.23
T
BayesDel_noAF
Benign
-0.56
CADD
Benign
1.6
DANN
Benign
0.92
DEOGEN2
Benign
0.15
T;.;.;T
Eigen
Benign
-0.89
Eigen_PC
Benign
-0.94
FATHMM_MKL
Benign
0.28
N
LIST_S2
Benign
0.81
T;T;T;.
M_CAP
Benign
0.012
T
MetaRNN
Benign
0.11
T;T;T;T
MetaSVM
Benign
-1.0
T
MutationAssessor
Benign
1.5
L;L;.;L
PhyloP100
0.93
PrimateAI
Benign
0.17
T
PROVEAN
Benign
-2.2
N;.;N;N
REVEL
Benign
0.018
Sift
Benign
0.057
T;.;T;T
Sift4G
Benign
0.083
T;T;T;T
Polyphen
0.21
B;B;.;B
Vest4
0.082
MutPred
0.38
Gain of catalytic residue at K738 (P = 0);Gain of catalytic residue at K738 (P = 0);Gain of catalytic residue at K738 (P = 0);Gain of catalytic residue at K738 (P = 0);
MVP
0.45
MPC
0.16
ClinPred
0.10
T
GERP RS
0.98
Varity_R
0.066
gMVP
0.33
Mutation Taster
=98/2
polymorphism

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

Other links and lift over

dbSNP: rs774817891; hg19: chr14-75514135; API