Alternative Names
Stones - cystine; Cystine stones
Definition of Cystinuria:
Cystinuria is a condition passed down through families in which stones form in the the kidney, ureter, and bladder. It is an autosomal recessive disorder.
See also: Nephrolithiasis
Causes, incidence, and risk factors:
Cystinuria is caused by excessive levels of an amino acid called cystine in the urine. After entering the kidneys, most cystine normally dissolves and goes back into the bloodstream. But persons with cystinuria have a genetic defect that interferes with this process. As a result, cystine builds up in the urine and forms crystals or stones, which may get stuck in the kidneys, ureters, or bladder.
Cystinuria affects approximately 1 out of 10,000 people. Cystine stones are most common in young adults under age 40. Less than 3% of known urinary tract stones are cystine stones.
