3-37040196-G-T

Variant names:

• chr3-37040196-G-T
• rs63751680
• NM_000249.4:c.1569G>T

Variant summary

Our verdict is Uncertain significance. The variant received 2 ACMG points: 4P and 2B. PM1 PM2 BP4 BP6

The NM_000249.4(MLH1):​c.1569G>T​(p.Glu523Asp) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). 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. E523E) has been classified as Likely benign.

• Frequency: Genomes: not found (cov: 32)
• Consequence: MLH1 NM_000249.4 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:3 B:2
• Conservation: PhyloP100: 3.20
• Publications: 9 publications found

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

ACMG classification

Our verdict: Uncertain_significance. The variant received 2 ACMG points.

• PM1: In a hotspot region, there are 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 2 benign, 53 uncertain in NM_000249.4
• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.30723125).
• BP6: Variant 3-37040196-G-T is Benign according to our data. Variant chr3-37040196-G-T is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 89792.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_000249.4. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	MLH1	NM_000249.4	MANE Select	c.1569G>T	p.Glu523Asp	missense	Exon 14 of 19	NP_000240.1
	MLH1	NM_001354628.2		c.1569G>T	p.Glu523Asp	missense	Exon 14 of 18	NP_001341557.1
	MLH1	NM_001354629.2		c.1470G>T	p.Glu490Asp	missense	Exon 13 of 18	NP_001341558.1

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	MLH1	ENST00000231790.8	TSL:1 MANE Select	c.1569G>T	p.Glu523Asp	missense	Exon 14 of 19	ENSP00000231790.3
	MLH1	ENST00000456676.7	TSL:1	c.1569G>T	p.Glu523Asp	missense	Exon 14 of 17	ENSP00000416687.3
	MLH1	ENST00000413740.2	TSL:1	c.1569G>T	p.Glu523Asp	missense	Exon 14 of 15	ENSP00000416476.2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 30

GnomAD4 genome Cov.: 32

Alfa AF: 0.0000858 Hom.: 0

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:3 Benign:2

Revision: criteria provided, conflicting classifications

Submissions by phenotype

not provided Uncertain:1 Benign:1

Apr 11, 2018

GeneDx

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant is considered likely benign or benign based on one or more of the following criteria: it is a conservative change, it occurs at a poorly conserved position in the protein, it is predicted to be benign by multiple in silico algorithms, and/or has population frequency not consistent with disease.

May 18, 2017

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Variant summary: The MLH1 c.1569G>T (p.Glu523Asp) variant causes a missense change involving the alteration of a conserved nucleotide. 3/4 in silico tools predict a benign outcome for this variant (SNPsandGO not captured due to low reliability index). Two functional studies showed that the mutation is not localized in, and does not create or disrupt any regulatory sequence (Lastella_BMC Genomics_2006) and that this variant maintained 76.6% in vitro MMR activity with >75% relative MLH1 expression (Takahashi_Cancer Res_2007). The neutrality of this variant has been suggested by computational studies (Chao_MSH2-MLH1_HM_2008, Lastella_BMC Genomics_2006). The variant of interest has not been found in a large, broad control population, ExAC in 121250 control chromosomes. One reputable database classified this variant as uncertain significance. The variant is classified as VUS until more functional studies and/or clinical information become available.

Hereditary cancer-predisposing syndrome Uncertain:1 Benign:1

Sep 07, 2018

Color Diagnostics, LLC DBA Color Health

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Jun 10, 2016

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.

Hereditary nonpolyposis colorectal neoplasms Uncertain:1

Jul 17, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces glutamic acid, which is acidic and polar, with aspartic acid, which is acidic and polar, at codon 523 of the MLH1 protein (p.Glu523Asp). This variant is not present in population databases (gnomAD no frequency). This missense change has been observed in individual(s) with Lynch syndrome (PMID: 28449805). ClinVar contains an entry for this variant (Variation ID: 89792). 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 with a negative predictive value of 95%. Experimental studies have shown that this missense change does not substantially affect MLH1 function (PMID: 17510385, 30998989). 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 v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.11
BayesDel_addAF	Pathogenic	0.19	D
BayesDel_noAF	Uncertain	0.030
CADD	Benign	18
DANN	Benign	0.80
DEOGEN2	Uncertain	0.67	D
Eigen	Benign	0.022
Eigen_PC	Benign	0.076
FATHMM_MKL	Pathogenic	0.97	D
LIST_S2	Uncertain	0.89	D
M_CAP	Benign	0.053	D
MetaRNN	Benign	0.31	T
MetaSVM	Benign	-0.92	T
MutationAssessor	Benign	1.3	L
PhyloP100		3.2
PrimateAI	Uncertain	0.58	T
PROVEAN	Benign	-1.3	N
REVEL	Uncertain	0.43
Sift	Benign	0.43	T
Sift4G	Benign	0.64	T
Polyphen		0.0	B
Vest4		0.56
MutPred		0.40		Gain of sheet (P = 0.0344)
MVP		0.96
MPC		0.061
ClinPred		0.47	T
GERP RS		5.0
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.30
gMVP		0.40
Mutation Taster		=69/31	polymorphism

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.060		Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Other links and lift over

dbSNP: rs63751680; hg19: chr3-37081687;