Abstract
INTRODUCTION: Myotonic dystrophy is a clinically and genetically heterogeneous multisystem disorder with a prevalence of 1 in 8000 in the general population. CASE PRESENTATION: A 25-year-old Ethiopian man presented with symptoms of myotonia, muscle wasting, gait problems, frontal baldness, and family history characterizing the hereditary disorder myotonic dystrophy. He had been on treatment for idiopathic generalized epilepsy for over 15 years. A needle electromyography showed insertional classic myotonic discharges. A nerve conduction study showed mild axonal sensorimotor polyneuropathy. His muscle biopsy showed marked increase of internalized nuclei, severely atrophic muscle fibers, muscle fiber necrosis and regeneration of isolated muscle fibers, architectural changes, and a preferential atrophy of type I fibers. CONCLUSION: This is a rare occurrence of two distinctive hereditary diseases.