Cystine calculi: challenging group of stones.

Cystinuria is an autosomal recessive disorder in renal tubular and intestinal transport of dibasic amino acids, which results in increased urinary excretion of cystine, ornithine, lysine and arginine. It affects 1 in 20 000 people and is caused by a defect in the rBAT gene on chromosome 2. Development of urinary tract cystine calculi is the only clinical manifestation of this disease. Owing to recurrent episodes of stone formation, these patients require a multi-modal approach to management. The role of medical management and minimally invasive surgery was reviewed for the treatment of cystinuria.