VNTR polymorphism of tyrosine hydroxylase gene and schizophrenia in the Korean population

This study aimed to test the association of the tyrosine hydroxylase (TH) gene with schizophrenia in the Korean population. 334 patients with schizophrenia and 391 healthy volunteers were included. Intron 1 VNTR polymorphism of TH gene was genotyped using polymerase chain reaction techniques. The genotype and allele distribution between patients and controls were not significantly different. However, the positive score of the Positive and Negative Syndrome Scale (PANSS) was higher in the group expressing the TH10 allele (t = 2.245, p = 0.02), although no significant differences were present in the distribution of age of onset, degree of improvement using Brief Psychiatric Rating Scale (BPRS) change, total PANSS score and negative score. This finding suggests that the TH10 allele may be a liability factor for positive schizophrenia in the Korean population.