A rare disorder involving severe damage to the brain and liver due to a deficiency of copper metabolism. It is one of the causes of mental retardation If this condition develops in childhood or early adolescence, it may run its course quickly and terminate in death within a few months or years. Afflicted children are excessively childish and emotionally labile (forced laughing and crying). They also have difficulty with swallowing and other voluntary movements. Cases developing later are characterized by cerebral impairment, contractures, hand tremors, and involuntary arm movements which sometimes become violent enough to be known as “wing beating.” Treatment is aimed at eliminating the excessive copper in the system through the administration of BAL (British Anti-Lewisite), penicillamine, and Versene. In some cases the motor symptoms can be alleviated, but the mental defect remains.See MENTAL RETARDATION (CAUSES).