McArdle's Disease

Abstract
The form of glycogen storage disease due to absence of muscle phosphorylase has a remarkable history. McArdle48 described the first case in 1951 and postulated that the disorder was due to a defect in glycogen breakdown. There were no further examples until 1959, when two cases were reported almost simultaneously. The enzymatic defect was clearly established in the investigation of these two cases by Pearson, Mommaerts, Rimer, and Illingworth in one50,58,59 and by Schmid, Mahler, Robbins, Larner, and Villar-Palasi in the other.40,68-70 This rapid elucidation of a disease is unparalled in medical annals. Although rare, the disease is important. It is the first of the hereditary myopathies in which the metabolic defect is known. Furthermore, investigations of the manifestations of the disease will provide important information regarding the role of glycogen in normal muscle metabolism. In addition, the existence of this disease has provided information regarding the