ABSTRACT
OBJECTIVES: Contemporary understanding of schizophrenia has evolved over the last century, yet its pathogenesis is not clear. Environmental stresses in early gestational period, which in turn, can cause neurodevelopmental abnormalities, is one possible etiologic factors in the development of schizophrenia. Heat shock protein 70(HSP70), which is thought to be a protective factor against environmental stresses in a cell, might be involved in the development of schizophrenia. Abnormal immunoreactivity to HSP70 has been identified in patients with schizophrenia. Therefore, genes for HSP70 might be candidates that affect susceptibility to schizophrenia. Three genes encoding HSP70 such as HSP70-1, HSP70-hom and HSP70-2 have been identified in the MHC class III region and they have been known to have genetic polymorphisms. We examined the association of schizophrenia and polymorphisms of HSP70-1, HSP70-hom and HSP70-2 genes in this study. METHODS: We investigated 161 patients with schizophrenia and 165 controls. DNA analysis with polymerase chain reaction(PCR) followed by enzyme restriction was used for the allelic typing of each polymorphism of HSP70-1, HSP70-hom and HSP70-2. The significances of genetic association of the polymorphisms with the disease and with clinical variables were estimated by chi-square test and analysis of variances. RESULTS: 1) There were no significant differences in allelic or genotype frequencies of HSP70-1 and HSP70-hom between the group of patients with schizophrenia and controls. 2) There was a tendency of difference in genotype frequency of HSP70-2, and a significant difference in allelic frequency of HSP70-2 between the group of patients with schizophrenia and controls. 3) There were no significant differences in terms of severity of symptoms and age at onset among the three HSP70 genotypes in the group of patients with schizophrenia. CONCLUSION: These results suggest that polymorphism of HSP70-2 might be related to the pathogenesis of schizophrenia.