Patients with Lesch-Nyhan disease almost always have behavior problems. Some of these troublesome behaviors include attempting to hit others, spitting on others, or using foul language. However, the Lesch-Nyhan variants do not have behavior problems.
These behaviors may look like acts of aggression towards others, but they are not. People with Lesch-Nyhan disease are not aggressive. Many admit that they are impulsive and cannot control these acts, and they are often apologetic after they do something bad. Despite their remorse about these bad behaviors, the impulses are often irresistible, and they can't control all of them.