EFFICACY AND SIDE-EFFECTS OF CLOZAPINE - TESTING FOR ASSOCIATION WITHALLELIC VARIATION IN THE DOPAMINE D-4 RECEPTOR GENE

Genetic factors are supposed to play a major role not only in the etio logy of psychiatric disorders but also in individual response to medic ations. To test the hypothesis that interindividual differences in res ponse to clozapine and the occurrence of side-effects might be influen ced by variations in the dopamine D-4 receptor gene, we examined frequ encies of four known polymorphic sites affecting protein structure in the dopamine D-4 receptor gene in 149 patients with schizophrenia or s chizoaffective disorder treated with clozapine. The D-4 polymorphisms included a 13-base pair deletion, which through a frameshift leads to a truncated nonfunctional receptor protein. There were, however, no si gnificant differences in genotype counts between responders and non-re sponders. Furthermore, no side-effect was found to be associated with genetic variants of the dopamine D-4 receptor. (C) 1996 American Colle ge of Neuropsychopharmacology