• Cystinosis can be confirmed by measuring the level of cystine in the white blood cells which is always elevated in a positive diagnosis.

• An ophthalmologist will make a slit lamp examination of the eyes to check for the presence of crystal deposits on the cornea.

• Prenatal diagnosis is available for families known to be at risk for having a child with Cystinosis.  Chorionic villus sampling is performed at 8-9 weeks of gestation and amniocentesis is performed at 14-16 weeks of gestation.