EXPRESSION AND CHARACTERIZATION OF A DOPAMINE D4R VARIANT ASSOCIATED WITH DELUSIONAL DISORDER

Multiple genetic polymorphisms of the human dopamine D4 receptor (hD4R ) have been identified including a 12 bp repeat in exon 1 associated w ith a psychotic condition called delusional disorder. Competition bind ing assays revealed minor pharmocological differences between the reco mbinant A1 (normal) and A2 (delusional) proteins with respect to quinp irole and the antipsychotic clozapine, however no functional differenc es were detected for receptor activation by dopamine, epinephrine, or norepinephrine. Our results suggest that this polymorphism may only co nfer susceptibility to delusional disorder in combination with other g enetic or environmental factors. (C) 1998 Federation of European Bioch emical Societies.