Cystinuria is a disorder of intestinal absorption and proximal renal tubular reabsorption of the dibasic amino acids - cystine, ornithine, arginine and lysine (remember COAL).
Inheritance is autosomal recessive with an incidence of 1 in 2500 live births in North America (1).
The dibasic amino acids are excreted in great excess in the urine of homozygotes.
This condition should not be confused with cystinosis or homocystinuria; the distinction between these conditions is often a subject of examination questions.
Last reviewed 01/2018