RESUMO
Myotonic dystrophy type 1 (DM1) or Steinert's disease (CIE-9-C: 359.21; CIE-10-ES: G71.11, ORPHA: 273) is a rare autosomal dominant inherited myopathy with almost complete penetrance and multisystemic consequences (neurological, cardiological, respiratory, endocrinological, and gastrointestinal). It is one of the clinical most variable diseases. The most bothersome symptoms for the patients (mobility problems, fatigue, hypersomnia, or gastrointestinal symptoms) and their families (apathy, lack of initiative) are not necessarily the most dangerous. Respiratory problems and cardiac arrhythmias shorten life expectancy. There is no specific treatment. The role of the Primary Care physician is crucial in the follow-up of DM1, either by coordinating the different professionals or detecting treatable complications. This work addresses the latter.