ANIONIC PHOSPHOLIPIDS CALCIUM-BINDING SITES IN DUCHENNE AND MURINE X-LINKED MUSCULAR-DYSTROPHY

Duchenne muscular dystrophy (DMD) and murine X-linked muscular dystrop hy (mdx) are genetically homologous and both characterized by absence of dystrophin. The function of this protein is not defined nor is the pathogenesis of the severe muscle necrosis and progressive weakness fo und in DMD but not in mdx. Recently we found that anionic phospholipid (AP) calcium binding sites are lacking at the muscle cell surface in DMD and we correlated these data with dystrophin deficiency and muscle necrosis. In order to verify the role of AP lack in the pathogenesis of muscle necrosis in DMD we studied the ultrastructural localization of these Ca++ receptors in mdx muscle membrane showing that they are n ormally represented as they are in control mouse and normal human musc le. The absence of AP in DMD compared with a normal distribution in md x suggests that these calcium binding site alterations play an importa nt and specific role in muscle fiber necrosis. (C) 1994 John Wiley & S ons, Inc.