CYP2D6 Gene Polymorphisms and Variable Metabolic Activity in Schizophrenia Patients of Han and Tibetan Populations

BACKGROUND: It has been suggested that the pharmacogenomic response to antipsychotics in schizophrenia patients partially contributed by drug metabolism enzyme polymorphism, including P450 2D6 (CYP2D6). However, CYP2D6 gene polymorphism across populations is largely unknown. MATERIALS AND METHODS: Here, we investigated the differences of CYP2D6 gene polymorphism between Chinese Han and Tibetan schizophrenia patients. We analyzed five CYP2D6 gene related polymorphic locus in 103 patients with schizophrenia, including 60 Han ethnicity and 43 of Tibetan ethnicity, by nucleic acid MALDI-TOF. RESULTS: Polymorphisms of rs1065852, rs1135840 and rs16947 were significantly different between Han and Tibetan patients. rs1065852 AA genotype had a low frequency of 9.3% in Tibetan patients in comparison with a frequency of 41.7% in Han patients, whereas rs16947 AA genotype had a low frequency of 3.3% in Han patients in comparison with a frequency of 34.9% in Tibetan patients. Additionally, the two patient groups showed distinct distribution of CYP2D6 haplotypes, with the highest frequency of *10/*10 and *1/*2 in Han and Tibetan patients, respectively. Furthermore, Han and Tibetan patients showed differential CYP2D6 metabolic activity. DISCUSSION: Taken together, this exploratory study showed the differences of CYP2D6 gene and metabolic polymorphism between Han and Tibetan schizophrenia patients, and therefore may improve our understanding of the pharmacogenomic response to antipsychotics in schizophrenia patients across populations.