chr14-75041625-C-T

Variant summary

Our verdict is Likely benign. The variant received -2 ACMG points: 0P and 2B. BP4BS1_Supporting

The NM_001040108.2(MLH3):​c.3455G>A​(p.Arg1152His) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000128 in 1,612,008 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 Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R1152C) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.000053 ( 0 hom., cov: 32)
Exomes 𝑓: 0.00014 ( 0 hom. )

Consequence

MLH3
NM_001040108.2 missense

Scores

1
6
12

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:6

Conservation

PhyloP100: 3.04

Publications

1 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: Likely_benign. The variant received -2 ACMG points.

BP4
Computational evidence support a benign effect (MetaRNN=0.31899607).
BS1
Variant frequency is greater than expected in population nfe. GnomAdExome4 allele frequency = 0.000136 (198/1460502) while in subpopulation NFE AF = 0.000169 (188/1110756). AF 95% confidence interval is 0.000149. There are 0 homozygotes in GnomAdExome4. There are 88 alleles in the male GnomAdExome4 subpopulation. Median coverage is 31. This position passed quality control check. Existence of Clinvar submissions makes me limit the strength of this signal to Supporting

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
MLH3NM_001040108.2 linkc.3455G>A p.Arg1152His missense_variant Exon 4 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.3455G>A p.Arg1152His missense_variant Exon 4 of 13 5 NM_001040108.2 ENSP00000348020.2 Q9UHC1-1

Frequencies

GnomAD3 genomes
AF:
0.0000528
AC:
8
AN:
151506
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.0000968
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:
0.0000589
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.0000636
AC:
16
AN:
251476
AF XY:
0.0000662
show subpopulations
Gnomad AFR exome
AF:
0.000123
Gnomad AMR exome
AF:
0.0000289
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.0000462
Gnomad NFE exome
AF:
0.000105
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.000136
AC:
198
AN:
1460502
Hom.:
0
Cov.:
31
AF XY:
0.000121
AC XY:
88
AN XY:
726660
show subpopulations
African (AFR)
AF:
0.0000299
AC:
1
AN:
33456
American (AMR)
AF:
0.0000671
AC:
3
AN:
44720
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26126
East Asian (EAS)
AF:
0.0000252
AC:
1
AN:
39694
South Asian (SAS)
AF:
0.0000116
AC:
1
AN:
86234
European-Finnish (FIN)
AF:
0.0000187
AC:
1
AN:
53414
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5766
European-Non Finnish (NFE)
AF:
0.000169
AC:
188
AN:
1110756
Other (OTH)
AF:
0.0000497
AC:
3
AN:
60336
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.448
Heterozygous variant carriers
0
9
17
26
34
43
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
10
20
30
40
50
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
GnomAD4 genome
AF:
0.0000528
AC:
8
AN:
151506
Hom.:
0
Cov.:
32
AF XY:
0.0000406
AC XY:
3
AN XY:
73916
show subpopulations
African (AFR)
AF:
0.0000968
AC:
4
AN:
41304
American (AMR)
AF:
0.00
AC:
0
AN:
15206
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3462
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5184
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4806
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10338
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000589
AC:
4
AN:
67892
Other (OTH)
AF:
0.00
AC:
0
AN:
2088
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.494
Heterozygous variant carriers
0
1
1
2
2
3
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome Het
Variant carriers
0
2
4
6
8
10
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
Alfa
AF:
0.0000915
Hom.:
0
Bravo
AF:
0.0000831
TwinsUK
AF:
0.000270
AC:
1
ALSPAC
AF:
0.00
AC:
0
ESP6500AA
AF:
0.00
AC:
0
ESP6500EA
AF:
0.000233
AC:
2
ExAC
AF:
0.0000659
AC:
8
EpiCase
AF:
0.000218
EpiControl
AF:
0.0000593

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:6
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

not specified Uncertain:2
Mar 04, 2025
Center for Genomic Medicine, Rigshospitalet, Copenhagen University Hospital
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Mar 07, 2025
Ambry Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The p.R1152H variant (also known as c.3455G>A), located in coding exon 3 of the MLH3 gene, results from a G to A substitution at nucleotide position 3455. The arginine at codon 1152 is replaced by histidine, an amino acid with highly similar properties. This amino acid position is well conserved in available vertebrate species. In addition, the in silico prediction for this alteration is inconclusive. The evidence for this gene-disease relationship is limited; therefore, the clinical significance of this alteration is unclear. -

Colorectal cancer, hereditary nonpolyposis, type 7 Uncertain:1
Dec 05, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces arginine, which is basic and polar, with histidine, which is basic and polar, at codon 1152 of the MLH3 protein (p.Arg1152His). This variant is present in population databases (rs374041909, gnomAD 0.009%). This variant has not been reported in the literature in individuals affected with MLH3-related conditions. ClinVar contains an entry for this variant (Variation ID: 544272). An algorithm developed to predict the effect of missense changes on protein structure and function (PolyPhen-2) suggests that this variant is likely to be tolerated. 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. -

Colorectal cancer;C0476089:Endometrial carcinoma;C1858380:Colorectal cancer, hereditary nonpolyposis, type 7 Uncertain:1
May 13, 2024
Fulgent Genetics, Fulgent Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

not provided Uncertain:1
Nov 03, 2021
Institute for Clinical Genetics, University Hospital TU Dresden, University Hospital TU Dresden
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

MLH3-related disorder Uncertain:1
Aug 05, 2024
PreventionGenetics, part of Exact Sciences
Significance:Uncertain significance
Review Status:no assertion criteria provided
Collection Method:clinical testing

The MLH3 c.3455G>A variant is predicted to result in the amino acid substitution p.Arg1152His. This variant has been reported in an individual with malignant mesothelioma (Table 2. Cheung et al. 2021. PubMed ID: 34008015). This variant is reported in 0.012% of alleles in individuals of African descent in gnomAD and is interpreted as a variant of uncertain significance in ClinVar (https://preview.ncbi.nlm.nih.gov/clinvar/variation/544272/). At this time, the clinical significance of this variant is uncertain due to the absence of conclusive functional and genetic evidence. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.11
BayesDel_addAF
Benign
-0.078
T
BayesDel_noAF
Benign
-0.11
CADD
Benign
23
DANN
Pathogenic
1.0
DEOGEN2
Benign
0.18
T;.;T
Eigen
Uncertain
0.40
Eigen_PC
Uncertain
0.49
FATHMM_MKL
Uncertain
0.93
D
LIST_S2
Uncertain
0.92
D;D;.
M_CAP
Benign
0.027
D
MetaRNN
Benign
0.32
T;T;T
MetaSVM
Benign
-0.69
T
MutationAssessor
Benign
1.7
L;L;L
PhyloP100
3.0
PrimateAI
Benign
0.35
T
PROVEAN
Uncertain
-2.6
D;.;D
REVEL
Uncertain
0.36
Sift
Benign
0.099
T;.;T
Sift4G
Benign
0.084
T;T;T
Polyphen
0.95
P;D;P
Vest4
0.33
MVP
0.89
MPC
0.17
ClinPred
0.24
T
GERP RS
5.9
Varity_R
0.12
gMVP
0.39
Mutation Taster
=63/37
polymorphism

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.060
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: rs374041909; hg19: chr14-75508328; API