Cystinosis is an autosomal recessive, metabolic disease in which the amino acid cystine accumulates in various organs of the body such as the kidney, eye, muscle, pancreas, and brain.
There are three clinical forms of cystinosis. Infantile (or nephropathic) cystinosis; late-onset cystinosis; and benign cystinosis.
Of these, infantile cystinosis is the most severe and usually diagnosed between 6 and 18 months of age. Common symptoms include excessive thirst and urination, failure to thrive, rickets, and episodes of dehydration. Children with cystinosis can also develop crystals in their eyes (after one year of age) and without specific treatment, develop end-stage renal failure may occur at approximately 9 years of age. Kidney transplantation has proven very helpful in patients with cystinosis.
Orphan drugs approved for cystinosis include
• Cystagon (cysteamine) and Procysbi (extended release cysteamine) are approved to nephropathic cystinosis.
• Cystaran (cysteamine eye drops) to treat corneal cysteine crystal accumulation in patients with cystinosis