3-37007057-G-C

Variant names:

Variant summary

Our verdict is Uncertain significance. The variant received 4 ACMG points: 4P and 0B. PM1PM2

The NM_000249.4(MLH1):c.447G>C(p.Gln149His) variant causes a missense change. The variant allele was found at a frequency of 0.00000137 in 1,460,750 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★★). Another nucleotide change resulting in the same amino acid substitution has been previously reported as Uncertain significance in ClinVar. Synonymous variant affecting the same amino acid position (i.e. Q149Q) has been classified as Likely benign.

Frequency

Genomes: not found (cov: 32)

Exomes 𝑓: 0.0000014 ( 0 hom. )

Consequence

MLH1
NM_000249.4 missense

Scores

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:3

Conservation

PhyloP100: 3.81

Publications

5 publications found

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]

MLH1 Gene-Disease associations (from GenCC):

Lynch syndrome
Inheritance: AD Classification: DEFINITIVE, SUPPORTIVE Submitted by: G2P, ClinGen, Orphanet
Lynch syndrome 2
Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: Ambry Genetics, Genomics England PanelApp
Muir-Torre syndrome
Inheritance: AD Classification: DEFINITIVE, STRONG, MODERATE, SUPPORTIVE Submitted by: Genomics England PanelApp, Ambry Genetics, G2P, Orphanet
mismatch repair cancer syndrome 1
Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Ambry Genetics, G2P, Labcorp Genetics (formerly Invitae), Orphanet, ClinGen
Lynch syndrome 1
Inheritance: AD Classification: STRONG Submitted by: Labcorp Genetics (formerly Invitae)
ovarian cancer
Inheritance: AD Classification: STRONG Submitted by: Genomics England PanelApp
malignant pancreatic neoplasm
Inheritance: AD Classification: MODERATE Submitted by: Genomics England PanelApp
rhabdomyosarcoma
Inheritance: AR Classification: MODERATE Submitted by: Genomics England PanelApp
prostate cancer
Inheritance: AD Classification: LIMITED Submitted by: Ambry Genetics
breast cancer
Inheritance: AD Classification: NO_KNOWN Submitted by: Ambry Genetics
hereditary breast carcinoma
Inheritance: AD Classification: NO_KNOWN Submitted by: ClinGen

MLH1 links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Uncertain_significance. The variant received 4 ACMG points.

PM1

In a hotspot region, there are 8 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 1 benign, 47 uncertain in NM_000249.4

PM2

Very rare variant in population databases, with high coverage;

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
MLH1	NM_000249.4 link	c.447G>C	p.Gln149His	missense_variant	Exon 5 of 19	ENST00000231790.8	NP_000240.1	P40692-1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
MLH1	ENST00000231790.8 link	c.447G>C	p.Gln149His	missense_variant	Exon 5 of 19	1	NM_000249.4	ENSP00000231790.3		P40692-1

Frequencies

GnomAD3 genomes

Cov.:

GnomAD2 exomes

AF:

0.00000398

AC:

AN:

251418

AF XY:

0.00

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.0000544

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.00000137

AC:

AN:

1460750

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

726776

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

33464

American (AMR)

AF:

0.00

AC:

AN:

44724

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26126

East Asian (EAS)

AF:

0.0000252

AC:

AN:

39688

South Asian (SAS)

AF:

0.00

AC:

AN:

86234

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53404

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5766

European-Non Finnish (NFE)

AF:

9.00e-7

AC:

AN:

1110984

Other (OTH)

AF:

0.00

AC:

AN:

60360

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.475

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

Cov.:

ExAC

AF:

0.00000824

AC:

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:3

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Lynch syndrome

Uncertain:1

Dec 01, 2023

All of Us Research Program, National Institutes of Health

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Hereditary nonpolyposis colorectal neoplasms

Uncertain:1

Dec 28, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This sequence change replaces glutamine, which is neutral and polar, with histidine, which is basic and polar, at codon 149 of the MLH1 protein (p.Gln149His). This variant is present in population databases (rs63750638, gnomAD 0.006%). This missense change has been observed in individual(s) with colorectal cancer (PMID: 17440950). ClinVar contains an entry for this variant (Variation ID: 90220). Invitae Evidence Modeling incorporating data from in vitro experimental studies (internal data) indicates that this missense variant is not expected to disrupt MLH1 function with a negative predictive value of 80%. 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. -

Hereditary cancer-predisposing syndrome

Uncertain:1

May 17, 2017

Ambry Genetics

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

The p.Q149H variant (also known as c.447G>C), located in coding exon 5 of the MLH1 gene, results from a G to C substitution at nucleotide position 447. The glutamine at codon 149 is replaced by histidine, an amino acid with highly similar properties. This alteration was detected in one individual, diagnosed with colon cancer at age 34, whose tumor demonstrated absence of the MLH1 protein and negative MLH1 promoter methylation (Ewald J et al. Br J Surg, 2007 Aug;94:1020-7). This amino acid position is well conserved in available vertebrate species. In addition, this alteration is predicted to be deleterious by in silico analysis. In addition, this alteration is predicted to be benign by MAPP-MMR in silico analyses (Chao EC et al. Hum. Mutat. 2008 Jun;29:852-60). Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Uncertain

0.37

BayesDel_addAF

Pathogenic

0.16

BayesDel_noAF

Pathogenic

0.17

CADD

Uncertain

(source)

DANN

Uncertain

1.0

DEOGEN2

Uncertain

0.77

D;.;T

Eigen

Uncertain

0.32

Eigen_PC

Uncertain

0.35

FATHMM_MKL

Pathogenic

0.98

LIST_S2

Pathogenic

0.98

D;D;D

M_CAP

Benign

0.082

MetaRNN

Uncertain

0.67

D;D;D

MetaSVM

Benign

-0.43

MutationAssessor

Pathogenic

3.2

M;.;.

PhyloP100

3.8

PrimateAI

Uncertain

0.70

PROVEAN

Uncertain

-3.4

D;D;D

REVEL

Pathogenic

0.71

Sift

Benign

0.032

D;D;D

Sift4G

Uncertain

0.036

D;D;D

Polyphen

0.97

D;.;.

Vest4

0.66

MutPred

0.37

Gain of sheet (P = 0.1208);.;.;

MVP

0.95

MPC

0.31

ClinPred

0.97

GERP RS

4.4

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

1.7

Varity_R

0.35

gMVP

0.85

Mutation Taster

=9/91

disease causing

(source)

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.020

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