ABSTRACT
Objective To explore the relationship between G-protein β3 subunit (GNB3) gene C825T polymor?phism and the weight gain of schizophrenics treated with olanzapine. Methods Ninety schizophrenics of first time hospi?talization were collected and treated with olanzapine for 12 weeks. The changes of body weight and body mass index (BMI) were detected before and after 12-week olanzapine treatment. The GNB3 gene C825T polymorphism in patients was determined by polymerase chain reaction (PCR) and DNA sequencing technique. The correlation of GNB3 gene C825T polymorphism and change of clinical parameters was analyzed. Results Body weight and BMI in patients were all increased significantly after treatment (all P<0.01). Weight gain rate (WGR) and increase of BMI in the TT genotype group were higher than those in the CC genotype group (all P<0.01). WGR and increase of BMI in the T-allele carrier (TT and CT genotypes) were higher than those in the T-allele non-carrier (CC genotype) (all P<0.01). There was signifi?cant difference in distribution of genotypes between WGR ≥7% group (CC 15.69%, CT 54.90%, TT 29.41%) and WGR <7% group (CC 38.46%, CT 43.59%, TT 17.95%) (P<0.05). The frequency of T-allele in the WGR≥7% group (63.33%) was higher than that in the WGR<7%group (39.74%) (P<0.05). Multi-variable linear regression indicated that TT genotype (contrasted with CC genotype) was an influential factor for change of body weight after treatment with olan?zapine (β=1.83, standardized β=0.29, P<0.01). Conclusions The GNB3 gene C825T polymorphism is associated with olanzapine-induced weight gain.