We report the case of a woman with myotonic dystrophy type 1, followed for 8 years after a Roux-en-Y gastric bypass. Weigh loss was substantial (53% of initial body weight) with functional improvement in spite of the natural course of the pathology. Five other cases have been published and have reported a relatively positive benefit/risk ratio. Precautions are to be taken at the time of anesthesia and follow-up in order to detect possible degradation of muscle function.
Keywords: Gastric bypass; Myotonic disease.