Polymorphisms of Interleukin-4 Promoter and Interleukin-4 Receptor Gene in Schizophrenic Patients

Choi, Jin Ouk; Jun, Tae Youn; Pae, Chi Un; Lee, Kyoung Uk

Abstract

OBJECTIVES
Recently, the main focus of etiologic study in schizophrenia has been directed to molecular genetic approach including polymorphism analysis. Abnormal immunoreactivity to IL-4 promoter and IL-4Ralpha has been identified in patients with schizophrenia. This study was designed to investigate the relationship between schizophrenia and immunologic influences by analyzing the polymorphisms of IL-4 promoter and IL-4Ralpha gene that are involved in interaction between immunologic system and CNS.
METHODS
222 schizophrenic patients diagnosed by DSM-IV and data of 165 normal controls obtained from Catholic Hemopoietic Stem Cell Information Bank, College of medicine, the Catholic University of Korea, were used in this study. DNA was extracted from whole blood and the polymorphic loci of IL-4 promoter and IL-4Ralphagene were amplified by polymerase chain reaction. Gene typing was performed by using SSCP and the results were assessed. The frequencies of allele and genotype were compared between patients and normal controls and between paranoid group and non-paranoid group. All data were analyzed chi2-test with two-tailed Fisher's exact test.
RESULTS
1) There were no significant differences in allele or genotype frequencies of IL-4 promoter and IL-4Ralpha between the group of schizophrenic patients and controls. 2) There were no significant differences in allele or genotype frequencies of IL-4 promoter and of IL-4Ralpaha between the group of paranoid schizophrenic patients and non-paranoid schizophrenic patients. CONCLSUION: These results suggest that polymorphisms of IL-4 promoter and IL-4Ralpha genes are unlikely related with the pathogenesis of schizophrenia.