Chinese Multicenter Clinical Outcome Cohort Study of Myotonic Dystrophy Type 1 (C-DMCOS-DM1)

Myotonic dystrophy type 1 (DM1) is an autosomal dominant multisystem disorder caused by an expanded CTG trinucleotide repeat in the 3' untranslated region of the DMPK gene. Beyond myotonia and progressive skeletal muscle weakness, DM1 involves the cardiac, respiratory, central nervous, gastrointestinal, endocrine, and ocular systems, and respiratory and cardiac involvement are the leading causes of disability and death. Systematic, long-term outcome data in Chinese DM1 patients are lacking. C-DMCOS-DM1 is a multicenter, prospective, observational cohort study that systematically records demographic data, multisystem involvement, and predefined disability-related clinical outcome events in genetically confirmed Chinese DM1 patients, with regular follow-up every 3 to 6 months. The study also collects residual blood, skeletal muscle, myocardium (when a pacemaker is implanted), and urine specimens for transcriptomic and other molecular studies. The aims are to characterize the disease burden of Chinese DM1 patients, identify risk and prognostic factors for disabling outcomes, and build risk-prediction models to inform follow-up, management, and future clinical trials.