Features of Cystinuria
1. Cystinuria is a stone disease in which the clinical phenotype follows an autosomal recessive pattern.
2. Reduced proximal tubule reabsorption of cystine and dibasic amino acids is present.
3. Hexagonal crystals may be seen in the urine.
4. First presentation is usually in childhood.
5. The mainstays of therapy are very high fluid intake, alkalinization of the urine, and the use of thiol-binding drugs such as tiopronin or D-penicillamine.
