AMP deaminase activity of skeletal muscle in neuromuscular disorders in childhood. Histochemical and biochemical studies.

We studied the histochemical staining and biochemical activity of AMP deaminase in biopsied muscle in Becker-type muscular dystrophy (BMD), Fukuyama-type congenital muscular dystrophy (FCMD), Duchenne-type muscular dystrophy (DMD), Werdnig-Hoffmann disease (WH) in order to elucidate the change of AMP deaminase activity in muscle with neuromuscular disorders in childhood. The intensity of AMP deaminase staining did not decrease in BMD with mild pathologic change, but in DMD, FCMD and WH it decreased in parallel with the severity of the pathologic change. The biochemical activity of AMP deaminase did not decrease in muscle with mild pathologic change in patients with DMD and tended to decrease according to the progress of the disease. The activity of AMP deaminase in muscle of patients with FCMD and WH which showed severe pathologic change was remarkably low. It was demonstrated that the decrease in the activity of AMP deaminase was related to the intensity of pathologic change rather than diagnosis of a neuromuscular disorder.