DefinitionLesch-Nyhan syndrome is an inheritable disorder that affects how the body builds and breaks down purines. Purines are a normal part of human tissue and help make up the body's genetic blueprint. They are also found in many different foods.Causes, incidence, and risk factorsLesch-Nyhan syndrome is inherited as an X-linked trait. It mostly occurs in boys. Persons with this syndrome are missing or are severely lacking an enzyme called hypoxanthine guanine phosphoribosyltransferase 1 (HGP). The body needs this enzyme to recycle purines. Without it, abnormally high levels of uric acid build up in the body.The condition affects about 1 in 380,000 people.SymptomsThe excess uric acid levels cause children to develop gout-like swelling in some of their joints. In some cases, kidney and bl