Association between PLA2G6 gene polymorphism for calcium-independent phospholipase A2 and nicotine dependence among males with schizophrenia.

We investigated the relationship between the rs10798059 (BanI) and rs4375 polymorphisms in the phospholipase A2 (PLA2)G4A and PLA2G6 genes and the risk of nicotine dependence in 263 Croatian patients with schizophrenia. We also examined whether interactions between these polymorphisms and smoking contributed to schizophrenia onset and Positive and Negative Syndrome Scale (PANSS) psychopathology. We found no significant differences in the distribution of PLA2G4A genotypes and alleles according to smoking status, and no effect of the PLA2G4A genotype-smoking interaction on disease onset or PANSS. The PLA2G6-TT homozygous genotype was significantly overrepresented in male smokers compared to nonsmokers (34.7% vs. 17.1%, p < 0.05). These patients had ∼2.6-fold higher risk of becoming smokers than males with heterozygous PLA2G6-CT and homozygous PLA2G6-CC genotypes. In addition, male smokers without the PLA2G6-C allele (PLA2G6-TT homozygous) experienced earlier onset than nonsmoking homozygous PLA2G6-TT males. Thus, the PLA2G6 polymorphism affected the risk of nicotine dependence in male patients and the PLA2G6 genotype-smoking interaction was linked to the age of disease onset.