Distal myopathy in nephropathic cystinosis

In long-standing nephropathic cystinosis complications are observed in vari ous organs. Distal myopathy was first described in detail in 1994. The prev alence was calculated to be 24%. We studied seven patients with nephropathi c cystinosis with neurophysiological techniques. Only two patients complain ed of a distal muscle weakness but all showed signs of myopathy on electrom yography, which was more pronounced in the distal muscles. Motor and sensor y nerve conduction parameters were within normal ranges. One patient with t he juvenile form of nephropathic cystinosis also had myopathy. We conclude that distal myopathy can be detected in nephropathic cystinosis even in the absence of clinically overt muscle weakness. Cystine-depleting therapy wit h cysteamine is recommended for all patients with cystinosis, even after re nal transplantation, and the effect on the myopathy should be studied.