14-75041625-C-T

Variant names:

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

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

MLH3 links:

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
MLH3	NM_001040108.2 link	c.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
MLH3	ENST00000355774.7 link	c.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:

AN:

151506

Hom.:

Cov.:

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:

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.:

Cov.:

AF XY:

0.000121

AC XY:

AN XY:

726660

show subpopulations

African (AFR)

AF:

0.0000299

AC:

AN:

33456

American (AMR)

AF:

0.0000671

AC:

AN:

44720

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26126

East Asian (EAS)

AF:

0.0000252

AC:

AN:

39694

South Asian (SAS)

AF:

0.0000116

AC:

AN:

86234

European-Finnish (FIN)

AF:

0.0000187

AC:

AN:

53414

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5766

European-Non Finnish (NFE)

AF:

0.000169

AC:

188

AN:

1110756

Other (OTH)

AF:

0.0000497

AC:

AN:

60336

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.448

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome Het

Variant carriers

<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:

AN:

151506

Hom.:

Cov.:

AF XY:

0.0000406

AC XY:

AN XY:

73916

show subpopulations

African (AFR)

AF:

0.0000968

AC:

AN:

41304

American (AMR)

AF:

0.00

AC:

AN:

15206

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3462

East Asian (EAS)

AF:

0.00

AC:

AN:

5184

South Asian (SAS)

AF:

0.00

AC:

AN:

4806

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10338

Middle Eastern (MID)

AF:

0.00

AC:

AN:

316

European-Non Finnish (NFE)

AF:

0.0000589

AC:

AN:

67892

Other (OTH)

AF:

0.00

AC:

AN:

2088

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.494

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Genome Het

Variant carriers

<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.:

Bravo

AF:

0.0000831

TwinsUK

AF:

0.000270

AC:

ALSPAC

AF:

0.00

AC:

ESP6500AA

AF:

0.00

AC:

ESP6500EA

AF:

0.000233

AC:

ExAC

AF:

0.0000659

AC:

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

BayesDel_noAF

Benign

-0.11

CADD

Benign

(source)

DANN

Pathogenic

1.0

DEOGEN2

Benign

0.18

T;.;T

Eigen

Uncertain

0.40

Eigen_PC

Uncertain

0.49

FATHMM_MKL

Uncertain

0.93

LIST_S2

Uncertain

0.92

D;D;.

M_CAP

Benign

0.027

MetaRNN

Benign

0.32

T;T;T

MetaSVM

Benign

-0.69

MutationAssessor

Benign

1.7

L;L;L

PhyloP100

3.0

PrimateAI

Benign

0.35

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

GERP RS

5.9

Varity_R

0.12

gMVP

0.39

Mutation Taster

=63/37

polymorphism

(source)

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

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Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

Age Distribution

Age Distribution

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over