Myotonic dystrophy type I or Steinert's disease is of autosomal dominant genetic origin. It is characterized by multisystemic alterations such as musculoskeletal, cardiac, ocular, and endocrine and the most manifest that are usually neurological.The diagnosis is established by clinical data, electromyography and genetic studies. So far the treatment is only symptomatic. The case of a family with Steinert's disease is presented, in which mother and son present the clinical and electromyographic manifestations of the disease.
