Clinical characteristics of 37 Chinese patients with myotonic dystrophy Type 1

This study aims to investigate clinical characteristics of 37 Chinese patients with Myotonic dystrophy Type 1 (DM1).Main clinical features of these cases were analyzed, with a focus on multi-system involvements.The median age of onset was 21.5 years, with a range from 3 to 45 years. Fourteen patients had a family history positive for DM1, whereas the other 23 were sporadic cases. Twenty-seven of the patients were male. The primary symptoms were myotonia and weakness with varying multi-system involvement including cardiac defects, cataracts, sleep disturbances, cholecystopathy, and peripheral neuropathy.This is the first report in China with the diagnosis of DM1 decisively confirmed by CTG expansion testing. Data from our study suggest that Chinese DM1 cases have different clinical characteristics compared with those of Caucasian cases, especially the prevalence of cardiac defects, cataracts, and sleep disturbances.