Pathogenesis refers to the study of how the defect in the hprt gene causes the problems that occur in Lesch-Nyhan disease. This research has provided some important answers, but there is still a lot to learn. This section describes the pathogensis of some of the main problems.

The research has already uncovered why patients with Lesch-Nyhan disease make so much uric acid. Much less is known about how errors in the hprt gene cause neurological and behavioral problems. We now know that most of the neurological and behavioral problems come from abnormal operations of a small area in the brain known as the basal ganglia. Exactly what is going on in this area, and what other brain regions might also be affected, is a very active area of current research. More information on this topic can be found in the Research section.