3-37048965-A-G

Variant names:

Variant summary

Our verdict is Uncertain significance. Variant got 4 ACMG points: 4P and 0B. PP3_Strong

The NM_000249.4(MLH1):c.2051A>G(p.Tyr684Cys) variant causes a missense change. The variant allele was found at a frequency of 0.000026 in 1,614,044 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 (★★).

Frequency

Genomes: 𝑓 0.000013 ( 0 hom., cov: 32)

Exomes 𝑓: 0.000027 ( 0 hom. )

Consequence

MLH1
NM_000249.4 missense

Scores

Clinical Significance

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

Conservation

PhyloP100: 6.81

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.

PP3

MetaRNN computational evidence supports a deleterious effect, 0.944

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
MLH1	NM_000249.4 link	c.2051A>G	p.Tyr684Cys	missense_variant	Exon 18 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.2051A>G	p.Tyr684Cys	missense_variant	Exon 18 of 19	1	NM_000249.4	ENSP00000231790.3		P40692-1

Frequencies

GnomAD3 genomes

AF:

0.0000131

AC:

AN:

152210

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

GnomAD3 exomes

AF:

0.0000159

AC:

AN:

251222

Hom.:

AF XY:

0.0000221

AC XY:

AN XY:

135764

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 SAS exome

AF:

0.0000980

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000274

AC:

AN:

1461834

Hom.:

Cov.:

AF XY:

0.0000248

AC XY:

AN XY:

727228

show subpopulations

Gnomad4 AFR exome

AF:

0.0000896

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.0000348

Gnomad4 FIN exome

AF:

0.0000187

Gnomad4 NFE exome

AF:

0.0000297

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

AF:

0.0000131

AC:

AN:

152210

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

74368

show subpopulations

Gnomad4 AFR

AF:

0.00

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.0000294

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.0000540

Hom.:

Bravo

AF:

0.00000378

ExAC

AF:

0.0000247

AC:

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:8

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Colorectal cancer, hereditary nonpolyposis, type 2

Uncertain:3

Nov 23, 2023

Baylor Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Mar 15, 2023

Myriad Genetics, Inc.

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant is classified as a variant of uncertain significance as there is insufficient evidence to determine its impact on protein function and/or cancer risk. -

Jul 19, 2017

Counsyl

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Hereditary cancer-predisposing syndrome

Uncertain:2

Apr 09, 2025

Color Diagnostics, LLC DBA Color Health

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This missense variant replaces tyrosine with cysteine at codon 684 of the MLH1 protein. Computational prediction suggests that this variant may have deleterious impact on protein structure and function. To our knowledge, functional studies have not been reported for this variant. This variant has been reported in an individual affected with Lynch syndrome (PMID: 18566915) and an individual affected with peritoneal cancer (PMID: 30093976). This variant has been identified in 6/282622 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. -

Jun 28, 2024

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The p.Y684C variant (also known as c.2051A>G), located in coding exon 18 of the MLH1 gene, results from an A to G substitution at nucleotide position 2051. The tyrosine at codon 684 is replaced by cysteine, an amino acid with highly dissimilar properties. This alteration has been reported in a Danish cohort of individuals diagnosed with colorectal cancer (Nilbert M et al. Fam. Cancer. 2009 Jun;8:75-83), in a Chinese patient diagnosed with peritoneal cancer who had a family history of stomach and breast cancer (Chan GHJ et al. Oncotarget 2018 Jul;9(55):30649-30660), in a cohort of 431 patients with wild-type PTEN who met at least the relaxed diagnostic criteria of the International Cowden Consortium (Lee YR et al. N Engl J Med, 2020 05;382:2103-2116), and in 1/1120 pediatric cancer patients who underwent whole genome sequencing and/or whole exome sequencing; this patient was diagnosed with hyperdiploid ALL (Zhang J et al. N Engl J Med, 2015 Dec;373:2336-2346). 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 variant remains unclear. -

Lynch syndrome

Uncertain:1

May 16, 2023

All of Us Research Program, National Institutes of Health

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This missense variant replaces tyrosine with cysteine at codon 684 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 Lynch syndrome (PMID: 18566915) and an individual affected with peritoneal cancer (PMID: 30093976). This variant has been identified in 6/282622 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

Apr 19, 2021

GeneDx

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; Observed in individuals with peritoneal cancer, leukemia, or familial colorectal cancer (Nilbert 2009, Zhang 2015, Chan 2018); This variant is associated with the following publications: (PMID: 25801821, 33309985, 26580448, 18566915, 30093976) -

Hereditary nonpolyposis colorectal neoplasms

Uncertain:1

Aug 08, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces tyrosine, which is neutral and polar, with cysteine, which is neutral and slightly polar, at codon 684 of the MLH1 protein (p.Tyr684Cys). This variant is present in population databases (rs267607886, gnomAD 0.01%). This missense change has been observed in individual(s) with biliary tract cancer, colon cancer, and/or peritoneal cancer (PMID: 18566915, 30093976, 36243179). ClinVar contains an entry for this variant (Variation ID: 90013). Advanced modeling performed at Invitae incorporating data from internal and/or published experimental studies (Invitae) indicates that this missense variant is not expected to disrupt MLH1 function with a negative predictive value of 95%. 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

Uncertain

0.36

BayesDel_addAF

Pathogenic

0.38

BayesDel_noAF

Pathogenic

0.51

CADD

Pathogenic

DANN

Uncertain

1.0

DEOGEN2

Pathogenic

0.92

D;.;.;.;.;.

Eigen

Pathogenic

0.88

Eigen_PC

Pathogenic

0.84

FATHMM_MKL

Uncertain

0.96

LIST_S2

Uncertain

0.96

D;D;.;.;.;D

M_CAP

Pathogenic

0.56

MetaRNN

Pathogenic

0.94

D;D;D;D;D;D

MetaSVM

Pathogenic

1.0

MutationAssessor

Pathogenic

3.7

H;.;.;.;.;.

PrimateAI

Uncertain

0.66

PROVEAN

Pathogenic

-7.8

D;D;D;D;D;D

REVEL

Pathogenic

0.93

Sift

Pathogenic

0.0

D;D;D;D;D;D

Sift4G

Uncertain

0.0020

D;D;D;D;D;D

Polyphen

1.0

D;.;.;.;.;.

Vest4

0.90

MutPred

0.76

Gain of catalytic residue at M682 (P = 0.0075);.;.;.;.;.;

MVP

0.97

MPC

0.45

ClinPred

1.0

GERP RS

5.9

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

1.7

Varity_R

0.96

gMVP

0.93

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