[Aggressive behavior, increasing loss of independence in mentally retarded patient].

Morbus Wilson is a rare autosomal recessive inborn error of metabolism which leads to an excessive deposition of copper many tissues. There are three types of presentation, an asymptomatic, a hepatic and a neurologic one. In this case report we present a 24-year-old man with mental retardation who showed changes in behaviour and slowness. Clinical and laboratory investigations confirmed the diagnosis of Morbus Wilson. We briefly review typical aspects of this rare disease.