DM1_DMPK

Gene
DMPK
Disease
DM1
Inheritance
AD
Classification
Definitive
Total Score
18
Publications Reviewed
7
Publication Span
30.58 years
Last Updated
07/21/2025
Curator(s)
Laurel Hiatt

Description

Myotonic dystrophy type 1 (DM1) is an autosomal dominant, multisystem repeat-expansion disorder caused by a pathogenic CTG expansion in the 3' UTR of DMPK. The locus-disease relationship is supported by molecularly confirmed DMPK CTG expansions in affected probands, population/control allele data, repeat-length and repeat interruptions that modify age at onset and severity, and experimental evidence showing toxic expanded CUG RNA with nuclear foci, RNA-binding protein sequestration, disease-relevant cellular and mouse phenotypes, and partial rescue after modulation of pathogenic RNA-binding pathways.

Genetic evidence

Total: 12

Collective EvidenceAllelePMID:32851192 PMID:396438392PMID:32851192 showed that DM1 individuals with repeat interruptions had milder motor/neurocognitive/behavioral outcomes than matched pure-repeat DM1 cases. PMID:39643839 summarizes that DMPK CTG expansion length influences disease severity/age at onset, while variant interruptions and somatic instability modify phenotype.
Singular EvidenceProbandsPMID:206351516In a Mexican cohort of 50 clinically/electrophysiologically diagnosed DM1 patients, 45/50 (90%) had pathogenic DMPK CTG expansions detected by fluorescent PCR plus TP-PCR/capillary electrophoresis; 400 unrelated controls showed non-expanded alleles ranging from 5 to 34 repeats.
StatisticsCase-control dataPMID:78470634Case-control study was carried out on 25 patients with myotonic dystrophy (MyD) and 25 healthy subjects (p < 0.0001).
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Experimental evidence

Total: 6

RescueRescue in non-human model organismPMID:399327942In CUG960 heart-specific DM1 mice expressing 960 interrupted CUG repeats in the human DMPK 3' UTR, AAV9-mediated MBNL1 and/or MBNL2 overexpression partially rescued conduction delays, contractile dysfunction, hypertrophy, and misregulated splicing/gene expression.
RescueRescue in cell culturePMID:160271111In 293T cells and myoblasts expressing an EGFP-(CUG)85 reporter, siRNA knockdown of hnRNP H restored EGFP expression and relieved nuclear retention of expanded CUG-repeat RNA; hnRNP H binding required expanded CUG repeats and a distal branch point.
ModelsNon-human model organismPMID:316499612DMSXL transgenic mice carrying a human DM1 allele with ~CTG1300 repeats yielded ALP-positive skeletal muscle pericytes that expressed transgenic DMPK and showed nuclear CUG RNA foci, averaging 1-2 foci/nucleus in heterozygotes and 5-10 in homozygotes.
Functional AlterationPatient cellsPMID:316499611ALP-positive skeletal muscle pericytes were isolated from six DM1 patients and two unaffected controls; patient pericytes showed nuclear CUG RNA foci with MBNL1 colocalization in several lines while maintaining proliferation and myogenic differentiation potential comparable to controls.
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Note: Maximum score caps apply at evidence type, category, and supercategory levels, so section totals may be lower than the raw sum of row scores.