Moreover, we found that rs1076560 T carrier/rs6314 CC individuals had better responses to antipsychotic treatment in two independent samples of patients with schizophrenia (n=63 and n=54, respectively), consistent with the previously reported separate effects of these genotypes.
The aim of the study was to investigate whether the 5-HT2A receptor gene's polymorphisms (His452Tyr and T102C) have an influence on the response to olanzapine in patients with schizophrenia.
Forty-nine patients, with schizophrenia or schizoaffective disorder and treated with clozapine (n = 22) or olanzapine (n = 27), were evaluated for fasting levels of C-peptide, insulin and blood glucose, homeostasis model assessment index for insulin resistance (HOMA-IR) and body mass index (BMI), and genotyped for the -1438A/G, -783A/G, 102T/C, and His452Tyr polymorphisms of the HTR2A gene.
Three polymorphisms in HTR2A, one silent (C102T), one that alters the amino acid sequence (his452tyr) and one in the promoter region (A-1437G) were investigated in 136 patients refractory or intolerant to treatment with typical antipsychotics and with a DSM-IIIR diagnosis of schizophrenia.
The authors examined the frequencies of gene polymorphisms in the 5-HT1A (Arg219Leu) and 5-HT2A (Thr25Asn and His452Tyr) receptor genes in 29 patients previously diagnosed with neuroleptic malignant syndrome, 94 neuroleptic-treated patients with schizophrenia who had no history of neuroleptic malignant syndrome, and 94 healthy comparison subjects.