Lack of association between polymorphisms in the 5-HT2A receptor gene and the antipsychotic response to clozapine.

OBJECTIVE: The authors' goal was to determine whether either of two 5-HT2A receptor polymorphisms, 102-T/C and 452-His/Tyr, are associated with clozapine response.
METHOD: Brief Psychiatric Rating Scale (BPRS) ratings were obtained in 70 patients with schizophrenia or schizoaffective disorder to determine their response to clozapine compared with a typical neuroleptic. Patients were genotyped with the polymerase chain reaction and restriction fragment length polymorphism analysis.
RESULTS: Neither 102-T/C nor 452-His/Tyr was associated with clozapine response. There were no significant differences in BPRS scores among patients with different 5-HT2A genotypes at week 10 of clozapine administration.
CONCLUSIONS: Allelic variation in the 5-HT2A gene is not associated with individual differences in clozapine response.