Purine Metabolism in Duchenne Muscular Dystrophy

Abstract

Duchenne muscular dystrophy (DMD) is the most widely known of the muscular dystrophies. It is inherited as an X-linked recessive trait (1). It becomes manifest only in males and it is transmitted by asymptomatic females, although there are exceptions (2). The primary manifestation is progressive muscle weakness, but there are more organs that are progressively affected, e.g. heart and brain. The primary gene defect is unknown but there is increasing evidence to suggest an abnormal sarcolemmal membrane (1). Leakage of ATP from muscles as found in the case of DMD patients (3) might lead to some defect in muscle purine metabolism. It was speculated that irreversible loss of purines, caused by the breakdown of ATP by enzymes in the blood, might be reduced by blocking the last enzymatic step in purine catabolism in man and by concommitant enhancement of purine reutilisation. This last step involves the xanthine oxidase reaction and allopurinol is widely used as an inhibitor of this reaction in the treatment of hyperuricemia. DMD patients receiving allopurinol were reported to improve clinically (4,5,6).