Tumor Necrosis Factor Alpha Gene Polymorphisms in Schizophrenia

Park, Ae Ja; Lee, Mi Kyung

Abstract

BACKGROUND: Schizophrenia may result from immune or inflammatory disorders, which are medi-ated by cytokines. Tumor necrosis factor-alpha(TNFalpha) is a pleotropic pro-inflammatory cytokine. Sequence polymorphism have been identified that could play a part in the transcriptional regula-tion of the gene. Two G -> A mutations in the promoter region of TNF alpha at position -308 (called the TNF2 allele) and -238 (TNFalpha 238A allele) have been described. In order to study whether polymor-phisms altering the function or expression of cytokine genes contribute to the pathogenesis of schizophrenia, we examined polymorphisms of TNF alpha genes in schizophrenic patients and com-pared them with those of healthy control subjects.
METHODS
We analyzed the polymorphisms of TNF alpha genes in 80 schizophrenic patients and 100 healthy control subjects. We used five primers and two separate PCR reactions to detect the TNF alpha polymorphism by the multiplex amplification refractory mutation system (ARMS) technique.
RESULTS
The frequencies of the TNF2 and TNF 238A allele in schizophrenic patients were 3.1% and 5.0% and in control subjects they were 5.0% and 6.0%. No statistically significant differences in TNF2 and TNF 238A allele frequencies were found among patients with schizophrenia and those under normal controls.
CONCLUSIONS
These findings suggest that the investigated polymorphisms of TNF alpha promoter gene do not appear to play any significant role as genetic risk factors in schizophrenia.