ABSTRACT
Relevant features of cystinosis Cystinosis is an autosomal-recessive disease that affects 1 in 100,000-200,000 live births. It is caused by the abnormal accumulation of cystine within various tissues. The nephropathic forms of cystinosis are associated with multi-organ damage, particularly progressive renal failure leading to dialysis and/or renal transplantation. To date, the only specific treatment for the nephropathic forms of cystinosis is cysteamine, which lowers intracellular cystine levels, thereby reducing the rate of progression of renal failure and significantly diminishing damage to other organs.1,2 Early complications include corneal crystals, poor growth, hypothyroidism and nephrocalcinosis. Late complications include myopathy, swallowing difficulties, pancreatic endocrine and exocrine insufficiency, retinal blindness, male hypogonadism, decreased pulmonary function and neurological deterioration.3 Cysteamine is unpleasant to take and causes gastrointestinal upset in many patients, but must be taken every 6 hours to have maximal effect. Despite its availability in capsule form for older children and the use of gastric acid inhibitors, there is a major problem with compliance, especially in adolescence.4 Further information can be obtained from the websites of the Cystinosis Foundation UK5 and the National Organization for Rare Disorders.6
