Children with Lesch-Nyhan disease often develop problem behaviors. The most troublesome of these involve repeated attempts to injure themselves, known as self-injurious behavior. These problems may start during the first year of life, but more commonly appear between 2-4 years of age. Biting of the lips and tongue is the most common problem behavior, but biting of fingers and other body parts may also occur. Others try to hit themselves or injure their own eyes.
The behaviors are very disturbing to anyone who may witness them. It is not helpful to try to get the behavior to stop by reasoning or punishment. It is very unhelpful to yell at the boy who is engaging in these behaviors. The impulses that force these behaviors to occur are too strong, and the boys cannot control them. It is necessary to restrain boys with Lesch-Nyhan disease when these behaviors appear, or they may cause serious injuries. In most cases, boys with Lesch-Nyhan disease prefer being restrained, because they are comforted by the knowledge that they will not hurt themselves.
Boys with Lesch-Nyhan disease can also have other disagreeable behaviors, such as hitting others, spitting on people, or using foul language. The Lesch-Nyhan variants do not have self-injurious behavior, and most do not exhibit the other difficult behaviors.