Abstract: Objective To investigate the association of Val279Phe missense mutation in the PAF-AH gene with genetic susceptibility to psoriasis vulgaris,and the role of single nucleotide polymorphisms of PAF-AH gene in the pathogenesis of psoriasis.Methods Genomic DNA was analyzed by the allele specific polymerase chain reaction for the Val279Phe mutation in patients with psoriasis and the healthy controls matched in age and sex.DNA sequencing was used to detect the PCR products with the mutant allele gene.Plasma PAF-AH activity was tested by PAF-AH assay kit.Results The prevalence of the mutation and the frequency of the mutation in the patients with psoriasis was not significantly different from those in the healthy controls (P>0.1).Plasma PAF-AH activity in the patients with psoriasis was significantly lower than that in the healthy controls(P<0.01).Conclusions The Resultssuggest that Val279Phe missense mutation in the PAF-AH gene has no significant relationship with psoriasis.It may not be a genetic risk factor for psoriasis in the Chinese patients.But it can result in significant deficiency of plasma PAF-AH activity.

Key words: Psoriasis, Hydrolases, Platelet activating factor, Mutation