[Pharmacogenetics focused on special phenotypes].

It is well-known that the patients with autosomal recessive juvenile Parkinsonism (ARJP), which is caused by the loss of function mutation in the Parkin gene, often show psychiatric symptoms such as depression, paranoia, psychosis, panic attacks, anorexia nervosa or suicide attempts. The recently established syndrome, dopamine dysregulation syndrome (DDS), is also frequently observed in the patients with ARJP. These facts might indicate that immature personality, which leads to reactive depression, anxiety, or suicide attempt, and vulnerability of reward system in ARJP, which leads to DDS, are due to loss of function of the Parkin gene product. The present status of molecular genetic studies on other special adverse effects of psychotropic medicines such as hyperammonemia due to valproate and malignant syndrome by antipsychotics was additionally reported.