Myopathy With Excessive Autophagy (MEAX)

Sugie et al. (2005) classified XMEA as a form of autophagic vacuolar myopathy, characterized by intracytoplasmic autophagic vacuoles with sarcolemmal features.The clinical course was mild; the patients suffered from slowly progressive muscle weakness mainly in the legs, but did not lose their ability to walk. There was no evidence of cardiac or neural involvement. Serum creatine kinase was elevated. By electron microscopy, an excessive number of autophagic vacuoles with staining properties of lysosomes were observed. The granular and membranous material contained in these vacuoles was actively exocytosed. The authors suggested that this disorder differed from the muscular dystrophy of Duchenne and Becker and of Emery-Dreifuss as well as from X-linked myotubular myopathy.