Variant 3-36993593-G-C details in Genebe, Genetics Data Aggregator

Variant summary

Our verdict is Uncertain significance. Variant got 4 ACMG points: 4P and 0B. PM1PP3_Moderate

The ENST00000231790.8(MLH1):c.46G>C(p.Val16Leu) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000889 in 1,461,884 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic 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. V16G) has been classified as Uncertain significance.

Frequency

Genomes: not found (cov: 33)

Exomes 𝑓: 0.0000089 ( 0 hom. )

Consequence

MLH1
ENST00000231790.8 missense

Scores

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:8

Conservation

PhyloP100: 9.49

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 4 ACMG points.

PM1

In a hotspot region, there are 4 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 2 benign, 17 uncertain in ENST00000231790.8

PP3

MetaRNN computational evidence supports a deleterious effect, 0.866

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
MLH1	NM_000249.4 linkuse as main transcript	c.46G>C	p.Val16Leu	missense_variant	1/19	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.46G>C	p.Val16Leu	missense_variant	1/19	1	NM_000249.4	ENSP00000231790	P1	P40692-1

Frequencies

GnomAD3 genomes

Cov.:

GnomAD3 exomes

AF:

0.00000398

AC:

AN:

251438

Hom.:

AF XY:

0.00

AC XY:

AN XY:

135914

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 SAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.00000889

AC:

AN:

1461884

Hom.:

Cov.:

AF XY:

0.00000688

AC XY:

AN XY:

727246

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.000302

Gnomad4 SAS exome

AF:

0.00

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.00

Gnomad4 OTH exome

AF:

0.0000166

GnomAD4 genome

Cov.:

ExAC

AF:

0.00000824

AC:

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:8

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	Aug 24, 2021	This missense variant replaces valine with leucine at codon 16 of the MLH1 protein. Computational prediction suggests that this variant may have deleterious impact on protein structure and function (internally defined REVEL score threshold >= 0.7, PMID: 27666373). To our knowledge, functional studies have not been reported for this variant. This variant has been reported in individuals affected with mesothelioma (PMID: 32206572), pancreatic cancer (PMID: 32980694), or Lynch syndrome associated cancers (PMID: 31386297) This variant has been identified in 1/251438 chromosomes in the general population by the Genome Aggregation Database (gnomAD) and in multiple healthy control individuals (PMID: 32980694). 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	Feb 02, 2024	The p.V16L variant (also known as c.46G>C), located in coding exon 1 of the MLH1 gene, results from a G to C substitution at nucleotide position 46. The valine at codon 16 is replaced by leucine, an amino acid with highly similar properties. This alteration was detected in patient with colon cancer at age 67 that was microsatellite stable with intact immunohistochemistry for the mismatch repair genes (Kiyozumi Y et al. Cancer Med, 2019 Sep;8:5534-5543). This amino acid position is highly conserved in available vertebrate species. In addition, this alteration is predicted to be deleterious by in silico analysis. Based on the available evidence, the clinical significance of this alteration remains unclear. -

not specified

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Genetic Services Laboratory, University of Chicago

Nov 13, 2019

- -

Colorectal cancer, hereditary nonpolyposis, type 2

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Baylor Genetics

Dec 11, 2023

- -

Lynch syndrome

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

All of Us Research Program, National Institutes of Health

Aug 13, 2024

This missense variant replaces valine with leucine at codon 16 of the MLH1 protein. Computational prediction suggests that this variant may have deleterious impact on protein structure and function (internally defined REVEL score threshold >= 0.7, PMID: 27666373). To our knowledge, functional studies have not been reported for this variant. This variant has been reported in an individual affected with colorectal with tumor data that demonstrated microsatellite stability and no loss of mismatch repair proteins via immunohistochemistry analysis (PMID: 31386297). This variant has been reported in individuals affected with mesothelioma (PMID: 32206572), unspecified cancers (PMID: 31386297), and in 1/1005 cases and 23/23705 controls in a large pancreatic cancer study (PMID: 32980694). This variant has been identified in 1/251438 chromosomes 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. -

not provided

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

GeneDx

Mar 21, 2023

Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports that this missense variant does not alter protein structure/function; This variant is associated with the following publications: (PMID: 28706299, 32206572, 22753075, 31386297) -

Muir-Torré syndrome

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Neuberg Centre For Genomic Medicine, NCGM

Jun 22, 2023

The observed missense variant c.46G>C(p.Val16Leu) in the MLH1 gene has not been reported previously as a pathogenic variant nor as a benign variant, to our knowledge. This variant is reported with the allele frequency 0.0004% in the gnomAD Exomes. This variant has been reported to the ClinVar database as Uncertain Significance. However, no details are available for independent assessment. The amino acid Val at position 16 is changed to a Leu changing protein sequence and it might alter its composition and physico- chemical properties. Multiple lines of computational evidence (Polyphen - Probably damaging, SIFT - Damaging and MutationTaster - Disease causing) predict a damaging effect on protein structure and function for this variant. The residue is conserved by GERP++ and PhyloP across 100 vertebrates. For these reasons, this variant has been classified as Uncertain Significance. -

Hereditary nonpolyposis colorectal neoplasms

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Oct 04, 2022

This sequence change replaces valine, which is neutral and non-polar, with leucine, which is neutral and non-polar, at codon 16 of the MLH1 protein (p.Val16Leu). This variant is present in population databases (rs776643257, gnomAD 0.006%). This missense change has been observed in individual(s) with colorectal cancer (PMID: 31386297). ClinVar contains an entry for this variant (Variation ID: 455439). Algorithms developed to predict the effect of missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be disruptive. 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. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Pathogenic

0.98

BayesDel_addAF

Pathogenic

0.36

BayesDel_noAF

Pathogenic

0.45

CADD

Pathogenic

DANN

Uncertain

1.0

DEOGEN2

Uncertain

0.75

Eigen

Uncertain

0.66

Eigen_PC

Uncertain

0.66

FATHMM_MKL

Pathogenic

0.99

LIST_S2

Pathogenic

0.99

M_CAP

Pathogenic

0.55

MetaRNN

Pathogenic

0.87

MetaSVM

Uncertain

0.58

MutationAssessor

Pathogenic

3.8

MutationTaster

Benign

1.0

PrimateAI

Pathogenic

0.85

PROVEAN

Uncertain

-2.4

REVEL

Pathogenic

0.85

Sift

Uncertain

0.0050

Sift4G

Uncertain

0.0090

Polyphen

1.0

Vest4

0.69

MutPred

0.55

Loss of MoRF binding (P = 0.0865);

MVP

0.98

MPC

0.33

ClinPred

0.99

GERP RS

5.1

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

1.6

Varity_R

0.86

gMVP

0.82

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