rs146777069

Positions:

Variant summary

Our verdict is Uncertain significance. Variant got 1 ACMG points: 2P and 1B. PM2BP4

The NM_000249.4(MLH1):c.954C>A(p.His318Gln) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000248 in 1,614,072 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 (★★). Synonymous variant affecting the same amino acid position (i.e. H318H) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 32)

Exomes 𝑓: 0.0000021 ( 0 hom. )

Consequence

MLH1
NM_000249.4 missense

Scores

Clinical Significance

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

Conservation

PhyloP100: -2.24

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 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Uncertain_significance. Variant got 1 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

BP4

Computational evidence support a benign effect (MetaRNN=0.39457625).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
MLH1	NM_000249.4 linkuse as main transcript	c.954C>A	p.His318Gln	missense_variant	11/19	ENST00000231790.8	NP_000240.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
MLH1	ENST00000231790.8 linkuse as main transcript	c.954C>A	p.His318Gln	missense_variant	11/19	1	NM_000249.4	ENSP00000231790	P1	P40692-1

Frequencies

GnomAD3 genomes

AF:

0.00000657

AC:

AN:

152196

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.0000654

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:

0.00

Gnomad OTH

AF:

0.00

GnomAD4 exome

AF:

0.00000205

AC:

AN:

1461876

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

727246

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.0000671

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.00

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.00

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

AF:

0.00000657

AC:

AN:

152196

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

74352

show subpopulations

Gnomad4 AFR

AF:

0.00

Gnomad4 AMR

AF:

0.0000654

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.00

Gnomad4 OTH

AF:

0.00

Bravo

AF:

0.00000378

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:6

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Hereditary cancer-predisposing syndrome

Uncertain:2

Uncertain significance, criteria provided, single submitter	clinical testing	Color Diagnostics, LLC DBA Color Health	Apr 22, 2023	This missense variant replaces histidine with glutamine at codon 318 of the MLH1 protein. Computational prediction suggests that this variant may not impact protein structure and function (internally defined REVEL score threshold <= 0.5, PMID: 27666373). To our knowledge, functional studies have not been reported for this variant. This variant has been reported in an individual affected with unilateral breast cancer (PMID: 33558524). This variant has not been identified in the general population by the Genome Aggregation Database (gnomAD). The available evidence is insufficient to determine the role of this variant in disease conclusively. Therefore, this variant is classified as a Variant of Uncertain Significance. -
Uncertain significance, criteria provided, single submitter	clinical testing	Ambry Genetics	Oct 13, 2022	The p.H318Q variant (also known as c.954C>A), located in coding exon 11 of the MLH1 gene, results from a C to A substitution at nucleotide position 954. The histidine at codon 318 is replaced by glutamine, an amino acid with highly similar properties. This amino acid position is highly conserved in available vertebrate species. In addition, the in silico prediction for this alteration is inconclusive. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -

Colorectal cancer, hereditary nonpolyposis, type 2

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Baylor Genetics

Oct 09, 2023

- -

Lynch syndrome

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

All of Us Research Program, National Institutes of Health

Jun 26, 2023

This missense variant replaces histidine with glutamine at codon 318 of the MLH1 protein. Computational prediction tools and conservation analyses are inconclusive regarding the impact of this variant on protein structure and function. Splice site prediction tools suggest that this variant may not impact RNA splicing. To our knowledge, functional studies have not been performed for this variant. This variant has not been reported in individuals affected with hereditary cancer in the literature. This variant has not been identified in the general population by the Genome Aggregation Database (gnomAD). The available evidence is insufficient to determine the role of this variant in disease conclusively. Therefore, this variant is classified as a Variant of Uncertain Significance. -

Hereditary nonpolyposis colorectal neoplasms

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Jun 01, 2022

This sequence change replaces histidine, which is basic and polar, with glutamine, which is neutral and polar, at codon 318 of the MLH1 protein (p.His318Gln). This variant is not present in population databases (gnomAD no frequency). This variant has not been reported in the literature in individuals affected with MLH1-related conditions. ClinVar contains an entry for this variant (Variation ID: 187486). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is not expected to disrupt MLH1 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. -

Familial cancer of breast

Uncertain:1

Uncertain significance, no assertion criteria provided

research

Center of Medical Genetics and Primary Health Care

Apr 08, 2020

ACMG Guidelines 2015 criteria PM1 Pathogenic Moderate: A functional DNA Mismatch Repair domain (I216-334L aa), which is an ATP binding site. Hot-spot has 36 non-VUS coding variants (22 pathogenic and 14 benign), pathogenicity = 61.1%, proximity score 11.279 > threshold 2.472. PM2 Pathogenic Moderate: Variant not found in GnomAD exomes. Variant not found in GnomAD genomes. PP2 Pathogenic Supporting: 198 out of 264 non-VUS missense variants in gene MLH1 are pathogenic = 75.0% > threshold of 51.0%, and 914 out of 2,356 clinically reported variants in gene MLH1 are pathogenic = 38.8% > threshold of 12.0%. BP4 Benign Supporting: 6 benign predictions from DANN, EIGEN, FATHMM-MKL, MVP, PrimateAI and REVEL vs 5 pathogenic predictions from DEOGEN2, M-CAP, MutationAssessor, MutationTaster and SIFT and the position is not conserved. Therefore, it has been classified as a variant of uncertain significance. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Pathogenic

0.75

BayesDel_addAF

Uncertain

0.15

BayesDel_noAF

Uncertain

-0.030

CADD

Benign

3.0

DANN

Uncertain

0.98

DEOGEN2

Uncertain

0.76

D;.;.;.;.;.;.

Eigen

Benign

-1.0

Eigen_PC

Benign

-1.2

FATHMM_MKL

Benign

0.15

LIST_S2

Pathogenic

0.98

D;D;.;.;.;D;D

M_CAP

Benign

0.025

MetaRNN

Benign

0.39

T;T;T;T;T;T;T

MetaSVM

Benign

-0.34

MutationAssessor

Uncertain

2.0

M;.;.;.;.;.;.

MutationTaster

Benign

0.96

D;D;D;D;D;D

PrimateAI

Pathogenic

0.79

PROVEAN

Pathogenic

-6.0

D;D;D;D;D;D;D

REVEL

Uncertain

0.45

Sift

Uncertain

0.0020

D;D;D;D;D;D;D

Sift4G

Uncertain

0.0060

D;D;D;D;D;T;D

Polyphen

1.0

D;.;.;.;.;.;.

Vest4

0.67

MutPred

0.45

Loss of sheet (P = 0.1158);.;.;.;.;.;.;

MVP

0.87

MPC

0.40

ClinPred

0.99

GERP RS

-9.6

Varity_R

0.78

gMVP

0.49

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

LitVar

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over