A - 308 promoter polymorphism of tumor necrosis factor alpha gene does not associate with the susceptibility to psoriasis vulgaris. No difference either between psoriasis type I and type II patients.

BACKGROUND: Genes encoded within the MHC complex on chromosome 6 are thought to play an important role in the pathogenesis of psoriasis. A potential candidate is tumor necrosis factor alpha (TNF-alpha) gene. Psoriasis features an increased activity of the proinflammatory cytokine TNF-alpha in affected lesions. TNF-alpha promoter region contains several polymorphisms, including G/A transition at position -308, which influences transcriptional activity of TNF-alpha. This study was performed to investigate the association between TNF-alpha single nucleotide polymorphism and susceptibility for psoriasis vulgaris.
MATERIAL AND METHODS: DNA from 78 patients with psoriasis vulgaris and 74 healthy volunteers with no personal and family history of psoriasis was investigated. TNF-alpha promoter gene single nucleotide polymorphism (SNP) in position 308 was evaluated by PCR-SSP. The results were compared between group of psoriatic patients, divided into early onset of psoriasis (type I) and late onset of psoriasis (type II) subgroups, and healthy subjects.
RESULTS: There were no significant differences in the polymorphism of TNF-alpha promoter -308 (genotype distribution, allele frequencies) between psoriasis patients and healthy controls. Similar results were obtained analyzing subgroups of psoriasis patients (type I and type II of psoriasis) and gender groups.
CONCLUSION: TNF-alpha promoter single nucleotide polymorphism (-308) is not associated with susceptibility to psoriasis vulgaris.