Recurrent Xanthine Stones in a Young Patient with Lesch-Nyhan Syndrome.

Lesch-Nyhan syndrome results from a rare X-linked inborn error of metabolism leading to a total body accumulation of uric acid. Clinical manifestations include self-mutilating behavior, poor muscle control, intellectual disability, gout, and kidney disease. Unfortunately, life expectancy is limited to the second or third decade of life because of symptoms associated with hyperuricemia, particularly renal failure. Patients with this condition frequently necessitate urologic intervention as the buildup of lithogenic substances predispose individuals to the development of kidney and bladder stones. We present the case of a 23-year-old white man with known Lesch-Nyhan syndrome and recurrent bilateral xanthine stones despite repeated urologic interventions. Therapy for Lesch-Nyhan syndrome consists of reduction of uric acid achieved through allopurinol. However, excess allopurinol dosing can lead to development of xanthine kidney and bladder stones. Thus, the treating clinician must maintain a delicate balance between managing hyperuricemia and avoiding xanthine urolithiasis.