Variant 3-36996655-TAA-TA details in Genebe, Genetics Data Aggregator

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:

MLH1 (HGNC:):

MLH1 links:

ACMG classification

Classification made for transcript

Verdict is Pathogenic. Variant got 18 ACMG points.

PVS1

Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.

PM2

Very rare variant in population databases, with high coverage;

PP5

Variant 3-36996655-TA-T is Pathogenic according to our data. Variant chr3-36996655-TA-T is described in ClinVar as [Pathogenic]. Clinvar id is 89793.Status of the report is reviewed_by_expert_panel, 3 stars. Variant chr3-36996655-TA-T is described in Lovd as [Pathogenic]. Variant chr3-36996655-TA-T is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
MLH1	NM_000249.4 linkuse as main transcript	c.156delA	p.Glu53fs	frameshift_variant	2/19	ENST00000231790.8	NP_000240.1	P40692-1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
MLH1	ENST00000231790.8 linkuse as main transcript	c.156delA	p.Glu53fs	frameshift_variant	2/19	1	NM_000249.4	ENSP00000231790.3		P40692-1

Frequencies

GnomAD3 genomes

Cov.:

GnomAD4 exome

AF:

6.84e-7

AC:

AN:

1461738

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

727166

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.0000116

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.00

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

Cov.:

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:10

Revision: reviewed by expert panel

LINK: link

Submissions by phenotype

Colorectal cancer, hereditary nonpolyposis, type 2

Pathogenic:3

Pathogenic, criteria provided, single submitter	clinical testing	Myriad Genetics, Inc.	Jul 11, 2023	This variant is considered pathogenic. This variant creates a frameshift predicted to result in premature protein truncation. -
Pathogenic, criteria provided, single submitter	clinical testing	Foundation for Research in Genetics and Endocrinology, FRIGE's Institute of Human Genetics	Aug 23, 2019	The heterozygous deletion c.156delA (p.Glu53ArgfsTer4) lies in exon 2 of the MLH1 gene and is predicted to cause a frameshift and consequent premature termination of the protein. The resultant protein is likely to lack the major functional domains of the protein, this will likely result in loss of function. The variant has been reported in the ClinVar database as pathogenic. The variant has been previously reported in patients affected with Lynch Syndrome and it is indicated to be disease causing. In summary, the variant meets our criteria to be classified as pathogenic. -
Pathogenic, criteria provided, single submitter	clinical testing	Neuberg Centre For Genomic Medicine, NCGM	May 20, 2023	The observed frameshift variant c.156del(p.Glu53ArgfsTer4) in MLH1 gene has been reported previously with MLH1-related conditions (Espenschied CR, et al.., 2017). The c.156del variant is absent in gnomAD Exomes. This variant has been reported to the ClinVar database as Likely Pathogenic / Pathogenic. However study on multiple affected individuals and functional studies on the pathogenicity of the variant is unavailable. This variant causes a frameshift starting with codon Glutamic Acid 53, changes this amino acid to Arginine residue, and creates a premature Stop codon at position 4 of the new reading frame, denoted p.Glu53ArgfsTer4. This variant is predicted to cause loss of normal protein function through protein truncation. Loss of function variants have been previously reported to be disease causing (Casey G,et al., 2005). For these reasons, this variant has been classified as Likely Pathogenic. -

Lynch syndrome

Pathogenic:3

Pathogenic, reviewed by expert panel	research	International Society for Gastrointestinal Hereditary Tumours (InSiGHT)	Sep 05, 2013	Coding sequence variation resulting in a stop codon -
Likely pathogenic, criteria provided, single submitter	clinical testing	Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine	Nov 16, 2021	The p.Glu53ArgfsX4 variant in MLH1 has been reported in an individual referred for genetic testing for Lynch Syndrome (Espenschied 2017 PMID: 28514183) and was absent from large population databases. This variant is predicted to cause a frameshift, which alters the protein’s amino acid sequence beginning at position 53 and leads to a premature termination codon 4 amino acids downstream. This alteration is then predicted to lead to a truncated or absent protein. Loss of function of the MLH1 gene is an established disease mechanism in autosomal dominant Lynch syndrome. Moreover, this variant was also classified as pathogenic on Sep 05, 2013 by the ClinGen-approved InSiGHT expert panel (Variation ID 89793). In summary, although additional studies are required to fully establish its clinical significance, this variant meets criteria to be classified as likely pathogenic for autosomal dominant Lynch syndrome. ACMG/AMP Criteria applied: PVS1, PM2_Supporting. -
Likely pathogenic, criteria provided, single submitter	clinical testing	Women's Health and Genetics/Laboratory Corporation of America, LabCorp	Jan 19, 2017	Variant summary: The MLH1 c.156delA (p.Glu53Argfs) variant results in a premature termination codon, predicted to cause a truncated or absent MLH1 protein due to nonsense mediated decay, which are commonly known mechanisms for disease. Truncations downstream of this position have been classified as pathogenic by our laboratory (e.g. c.1210_1211delCT, p.Leu404fs). One in silico tool predicts a damaging outcome for this variant. This variant is absent in 121360 control chromosomes. In addition, multiple clinical diagnostic laboratories/reputable databases classified this variant as pathogenic. The variant of interest has not, to our knowledge, been reported in affected individuals via publications nor evaluated for functional impact by in vivo/vitro studies. Taken together, this variant is classified as likely pathogenic. -

Hereditary cancer-predisposing syndrome

Pathogenic:2

Pathogenic, criteria provided, single submitter	clinical testing	Color Diagnostics, LLC DBA Color Health	Jan 28, 2021	This variant deletes 1 nucleotide in exon 2 of the MLH1 gene, creating a frameshift and premature translation stop signal. This variant is expected to result in an absent or non-functional protein product. This variant has been reported in a family affected with Lynch syndrome (Elias 2017, doi.org/10.24870/cjb.2017-a238). Eight members of this family were identified as carriers, of which three members were affected (age of onset <30 years in one individual and >40 years in two individuals). This variant has not been identified in the general population by the Genome Aggregation Database (gnomAD). Loss of MLH1 function is a known mechanism of disease (clinicalgenome.org). Based on the available evidence, this variant is classified as Pathogenic. -
Pathogenic, criteria provided, single submitter	clinical testing	Ambry Genetics	Mar 31, 2022	The c.156delA pathogenic mutation, located in coding exon 2 of the MLH1 gene, results from a deletion of one nucleotide at nucleotide position 156, causing a translational frameshift with a predicted alternate stop codon (p.E53Rfs*4). This variant is considered to be rare based on population cohorts in the Genome Aggregation Database (gnomAD). This alteration is expected to result in loss of function by premature protein truncation or nonsense-mediated mRNA decay. As such, this alteration is interpreted as a disease-causing mutation. -

not provided

Pathogenic:1

Likely pathogenic, no assertion criteria provided

clinical testing

Mayo Clinic Laboratories, Mayo Clinic

- -

Hereditary nonpolyposis colorectal neoplasms

Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Aug 20, 2023

For these reasons, this variant has been classified as Pathogenic. ClinVar contains an entry for this variant (Variation ID: 89793). This premature translational stop signal has been observed in individual(s) with MLH1-related conditions (PMID: 15713769, 24362816, 28514183). This variant is not present in population databases (gnomAD no frequency). This sequence change creates a premature translational stop signal (p.Glu53Argfs*4) in the MLH1 gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in MLH1 are known to be pathogenic (PMID: 15713769, 24362816). -

Computational scores

Source: dbNSFP v4.3

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Splicing

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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.

3-36996655-TAA-TA

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

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