rs63750855

Variant summary

Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PVS1PM2PP5_Very_Strong

The NM_000249.4(MLH1):​c.1489del​(p.Arg497GlyfsTer11) variant causes a frameshift change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,844 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Pathogenic (★★★). Variant results in nonsense mediated mRNA decay.

Frequency

Genomes: not found (cov: 32)
Exomes 𝑓: 6.8e-7 ( 0 hom. )

Consequence

MLH1
NM_000249.4 frameshift

Scores

Not classified

Clinical Significance

Pathogenic reviewed by expert panel P:5

Conservation

PhyloP100: 0.659
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]

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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 3-37028857-AC-A is Pathogenic according to our data. Variant chr3-37028857-AC-A is described in ClinVar as [Pathogenic]. Clinvar id is 89752.Status of the report is reviewed_by_expert_panel, 3 stars. Variant chr3-37028857-AC-A is described in Lovd as [Likely_pathogenic]. Variant chr3-37028857-AC-A is described in Lovd as [Pathogenic]. Variant chr3-37028857-AC-A is described in Lovd as [Pathogenic]. Variant chr3-37028857-AC-A is described in Lovd as [Likely_pathogenic].

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect #exon/exons MANE Protein UniProt
MLH1NM_000249.4 linkuse as main transcriptc.1489del p.Arg497GlyfsTer11 frameshift_variant 13/19 ENST00000231790.8 NP_000240.1

Ensembl

Gene Transcript HGVSc HGVSp Effect #exon/exons TSL MANE Protein Appris UniProt
MLH1ENST00000231790.8 linkuse as main transcriptc.1489del p.Arg497GlyfsTer11 frameshift_variant 13/191 NM_000249.4 ENSP00000231790 P1P40692-1

Frequencies

GnomAD3 genomes
Cov.:
32
GnomAD3 exomes
AF:
0.00000398
AC:
1
AN:
251484
Hom.:
0
AF XY:
0.00000736
AC XY:
1
AN XY:
135912
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad SAS exome
AF:
0.0000327
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
6.84e-7
AC:
1
AN:
1461844
Hom.:
0
Cov.:
32
AF XY:
0.00000138
AC XY:
1
AN XY:
727224
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.:
32

ClinVar

Significance: Pathogenic
Submissions summary: Pathogenic:5
Revision: reviewed by expert panel
LINK: link

Submissions by phenotype

Colorectal cancer, hereditary nonpolyposis, type 2 Pathogenic:2
Pathogenic, criteria provided, single submitterclinical testingKCCC/NGS Laboratory, Kuwait Cancer Control CenterJul 07, 2023MLH1 (Arg497fs): This sequence change creates a premature translational stop signal (p.Arg497Glyfs*11) in the MLH1 gene. It is expected to result in an absent or disrupted protein product. The frequency data for this variant in the population databases is considered unreliable, as metrics indicate poor data quality at this position in the ExAC database. This variant has been reported in individuals affected with Lynch syndrome and Muir-Torre syndrome (PMID: 15872200, 18270343). ClinVar contains an entry for this variant (Variation ID: 89752) with 3 submissions, all pathogenic, 3 stars, no conflict, and reviewed by an expert panel. Loss-of-function variants in MLH1 are known to be pathogenic (PMID: 15713769, 24362816). Therefore, this variant has been classified as Pathogenic. . -
Pathogenic, criteria provided, single submitterclinical testingMyriad Genetics, Inc.Jul 20, 2023This variant is considered pathogenic. This variant creates a frameshift predicted to result in premature protein truncation. -
Lynch syndrome Pathogenic:1
Pathogenic, reviewed by expert panelresearchInternational Society for Gastrointestinal Hereditary Tumours (InSiGHT)Sep 05, 2013Coding sequence variation resulting in a stop codon -
Hereditary nonpolyposis colorectal neoplasms Pathogenic:1
Pathogenic, criteria provided, single submitterclinical testingLabcorp Genetics (formerly Invitae), LabcorpDec 07, 2020For these reasons, this variant has been classified as Pathogenic. Loss-of-function variants in MLH1 are known to be pathogenic (PMID: 15713769, 24362816). This variant has been reported in individuals affected with Lynch syndrome and Muir-Torre syndrome (PMID: 15872200, 18270343). ClinVar contains an entry for this variant (Variation ID: 89752). The frequency data for this variant in the population databases is considered unreliable, as metrics indicate poor data quality at this position in the ExAC database. This sequence change creates a premature translational stop signal (p.Arg497Glyfs*11) in the MLH1 gene. It is expected to result in an absent or disrupted protein product. -
Hereditary cancer-predisposing syndrome Pathogenic:1
Pathogenic, criteria provided, single submitterclinical testingAmbry GeneticsDec 30, 2021The c.1489delC pathogenic mutation, located in coding exon 13 of the MLH1 gene, results from a deletion of one nucleotide at nucleotide position 1489, causing a translational frameshift with a predicted alternate stop codon (p.R497Gfs*11). This mutation was identified in a patient with colorectal cancer at 46 and Muir-Torre phenotype (Hampel H et al. N. Engl. J. Med. 2005 May;352:1851-60; South CD et al. J. Natl. Cancer Inst. 2008 Feb;100:277-81). This mutation was also reported in a patient with endometrial cancer showing absent MLH1 and PMS2 protein expression by immunohistochemistry (Moline J et al. Gynecol. Oncol. 2013 Jul;130:121-6). In addition to the clinical data presented in the literature, 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. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction

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.

Other links and lift over

dbSNP: rs63750855; hg19: chr3-37070348; API