Therapy of Cystinosis

Abstract

Cystinosis is a recessively inherited disorder characterized by an accumulation of free cystine within lysosomes. The lysosome is a major site of intracellular protein degradation, which results in the release of free amino acids that must pass through the lysosomal membrane to the cytosol. Lysosomal cystine efflux requires a specific transport system that is defective in cystinosis. This defect has been demonstrated in lysosomes from peripheral-blood leukocytes, cultured skin fibroblasts, and Epstein–Barr virus—transformed lymphoblasts from patients with this disorder, and has been verified in three separate laboratories.^{1 2 3 4 5} Patients with infantile nephropathic cystinosis present for medical attention at 8 to 15 . . .