NM_001040108.2:c.2197T>G

Variant names:

Variant summary

Our verdict is Likely benign. The variant received -5 ACMG points: 0P and 5B. BP4_StrongBP6

The NM_001040108.2(MLH3):c.2197T>G(p.Leu733Val) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000118 in 1,614,142 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 15/22 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. L733S) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.000013 ( 0 hom., cov: 33)

Exomes 𝑓: 0.000012 ( 0 hom. )

Consequence

MLH3
NM_001040108.2 missense

Scores

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:1B:1

Conservation

PhyloP100: 0.333

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

MLH3 links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Likely_benign. The variant received -5 ACMG points.

BP4

Computational evidence support a benign effect (MetaRNN=0.024110526).

BP6

Variant 14-75047459-A-C is Benign according to our data. Variant chr14-75047459-A-C is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 410899.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
MLH3	NM_001040108.2 link	c.2197T>G	p.Leu733Val	missense_variant	Exon 2 of 13	ENST00000355774.7	NP_001035197.1	Q9UHC1-1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	UniProt
MLH3	ENST00000355774.7 link	c.2197T>G	p.Leu733Val	missense_variant	Exon 2 of 13	5	NM_001040108.2	ENSP00000348020.2	Q9UHC1-1
MLH3	ENST00000380968.6 link	c.2197T>G	p.Leu733Val	missense_variant	Exon 2 of 12	1		ENSP00000370355.3	Q9UHC1-2
MLH3	ENST00000556257.5 link	c.2197T>G	p.Leu733Val	missense_variant	Exon 2 of 7	5		ENSP00000451540.1	G3V419

Frequencies

GnomAD3 genomes

AF:

0.0000131

AC:

AN:

152216

Hom.:

Cov.:

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:

0.0000294

Gnomad OTH

AF:

0.00

GnomAD2 exomes

AF:

0.0000239

AC:

AN:

251364

AF XY:

0.0000294

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.0000289

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000176

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000116

AC:

AN:

1461808

Hom.:

Cov.:

AF XY:

0.0000179

AC XY:

AN XY:

727198

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

33480

American (AMR)

AF:

0.0000224

AC:

AN:

44724

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26132

East Asian (EAS)

AF:

0.00

AC:

AN:

39684

South Asian (SAS)

AF:

0.0000464

AC:

AN:

86256

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53382

Middle Eastern (MID)

AF:

0.000173

AC:

AN:

5768

European-Non Finnish (NFE)

AF:

0.00000719

AC:

AN:

1111988

Other (OTH)

AF:

0.0000497

AC:

AN:

60394

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.487

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:

0.0000131

AC:

AN:

152334

Hom.:

Cov.:

AF XY:

0.0000134

AC XY:

AN XY:

74496

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

41578

American (AMR)

AF:

0.00

AC:

AN:

15292

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3472

East Asian (EAS)

AF:

0.00

AC:

AN:

5192

South Asian (SAS)

AF:

0.00

AC:

AN:

4830

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10622

Middle Eastern (MID)

AF:

0.00

AC:

AN:

294

European-Non Finnish (NFE)

AF:

0.0000294

AC:

AN:

68028

Other (OTH)

AF:

0.00

AC:

AN:

2114

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.425

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Alfa

AF:

0.00

Hom.:

Bravo

AF:

0.0000151

ExAC

AF:

0.0000330

AC:

Asia WGS

AF:

0.000289

AC:

AN:

3478

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:1Benign:1

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

Colorectal cancer, hereditary nonpolyposis, type 7

Uncertain:1

Aug 27, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This sequence change replaces leucine, which is neutral and non-polar, with valine, which is neutral and non-polar, at codon 733 of the MLH3 protein (p.Leu733Val). This variant is present in population databases (rs566653064, gnomAD 0.01%). 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: 410899). An algorithm developed to predict the effect of missense changes on protein structure and function outputs the following: PolyPhen-2: "Benign". The valine amino acid residue is found in multiple mammalian species, which suggests that this missense change does not adversely affect protein function. 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. -

not specified

Benign:1

Mar 27, 2025

Ambry Genetics

Significance:Likely benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This 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. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.074

BayesDel_addAF

Benign

-0.44

BayesDel_noAF

Benign

-0.66

CADD

Benign

0.18

(source)

DANN

Uncertain

0.98

DEOGEN2

Benign

0.087

T;.;.;T

Eigen

Benign

-1.1

Eigen_PC

Benign

-1.0

FATHMM_MKL

Benign

0.11

LIST_S2

Benign

0.64

T;T;T;.

M_CAP

Benign

0.0019

MetaRNN

Benign

0.024

T;T;T;T

MetaSVM

Benign

-1.0

MutationAssessor

Benign

1.1

L;L;.;L

PhyloP100

0.33

PrimateAI

Benign

0.28

PROVEAN

Benign

-0.30

N;.;N;N

REVEL

Benign

0.012

Sift

Benign

0.20

T;.;T;T

Sift4G

Benign

0.60

T;T;T;T

Polyphen

0.0030

B;B;.;B

Vest4

0.054

MutPred

0.33

Gain of catalytic residue at K738 (P = 0.0036);Gain of catalytic residue at K738 (P = 0.0036);Gain of catalytic residue at K738 (P = 0.0036);Gain of catalytic residue at K738 (P = 0.0036);

MVP

0.23

MPC

0.11

ClinPred

0.11

GERP RS

-0.59

Varity_R

0.043

gMVP

0.21

Mutation Taster

=99/1

polymorphism

(source)

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

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Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

Age Distribution

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over