Variability of multisystemic features in myotonic dystrophy type 1 – Lessons from Serbian registry

Background: Myotonic dystrophy type 1 (DM1) is a rare disease. Creating registry for such a disease is of outstanding importance since it provides us with a full spectrum of the disorder. Aim: To assess variability of different multisystemic features in a large cohort of patients with DM1. Patients and Method: Data from the Serbian registry for myotonic dystrophies were used in the study. Final number of included DM1 subjects was 275. Results: Registry included 53.8% of male patients. Age at enrollment was 47.2±9.9 years, mean disease duration 20.4±9.9 years, and mean CTG repeats number 598.3±269.8.Progression of muscle weakness was pretty slow, slower in proximal than distal muscles, and slower in arms than in legs. Severe ECG abnormality was found in 25.0% of patients and pacemaker was implanted in 9.5%. Lens opacities were observed in 83.5% of DM1 patients and 35.3% had ocular hypotony. Metabolic disturbances were very common, while 19.5% of patients had hypokalemia and 37.8% hypochloremia. Sterility was found in 20.5% of males and 4.1% of females. Cholelithiasis was found in 36.4% of patients and constipation in 29.9%. Conclusions: We defined the most common characteristics of our DM1 patients and observed some treatable symptoms that have been neglected previously. Certain findings deserve further investigations in terms of their causes and consequences. Besides this, presented data analysis directs us to make further improvements of the registry.