Journal of the Korean Society of Biological Psychiatry  1999;6(2):170-175

VNTR Polymorphism of Tyrosine Hydroxylase Gene Intron 1 in Schizophrenics.

In Ho PAIK ; Kyu Young TOH ; Chang Uk LEE ; Jung Jin KIM ; Soo Jung LEE ; Chul LEE

Keywords

Schizophrenia; Tyrosine hydroxylase; Genetics; Association

Country

Republic of Korea

Language

Korean

Abstract

Until recently, the etiology of schizophrenia was generally attributed to abnormalities in dopaminergic neurotransmission. Specifically, an excess of dopaminergic activity in the mesolimbic system has been postulated to produce the positive symptoms, while decreased dopaminergic activity in the mesocortical system has been suggested to cause negative symptoms. Accordingly, we performed an association study of schizophrenia with TH gene. Three hundred and seventy four biologically unrelated schizophrenic patients meeting DSM-III-R criteria from Kangnam St. Mary's Hospital affiliated with Catholic university of Korea were recruited for our study. The 393 healthy controls were volunteers for DNA library of Kangnam St. Mary's Hospital without personal or family history of psychiatric and neurologic illness. DNA was extracted from peripheral mononuclear cells and polymorphic region was amplified by polymerase chain reaction. TH intron 1 VNTR polymorphism was typed by silver staining. The allele distributions of TH gene were not different between schizophrenics and controls. However, the frequency of allele A was significantly higher in positive group than that of negative group of schizophrenics. These findings suggest that poitive schizophrenia may be associated with allele A of TH gene.