Analysis of single nucleotide polymorphisms of methylenetetrahydrofolate reductase in Japanese psoriasis patients

Methotrexate (MTX) is an effective drug for the treatment of psoriasis as well as rheumatoid arthritis. We investigated the correlation between single nucleotide polymorphisms (SNP) in methylenetetrahydrofolate reductase (MTHFR) and susceptibility to psoriasis in 175 psoriasis patients and 150 healthy controls and between MTHFR SNP and responsiveness to psoriasis treatment in 7 psoriasis patients. The frequencies of the 677C allele in the patient and healthy control groups were 0.61 and 0.57, respectively, while those of the 677T allele were 0.39 and 0.43, respectively. Both allele frequencies in both groups were not significantly different. Moreover, both groups showed the same frequency of 1298A allele (0.83 vs. 0.83) and 1298C allele (0.17 vs. 0.17). The frequency of MTHFR SNP and susceptibility to psoriasis were not correlated. Additionally, MTHFR SNP frequency and the psoriasis lesion were not correlated. Investigation of the MTX treatment efficacy in 7 patients revealed that the drug was effective in psoriasis patients with positive presumed 677C–1298A SNP haplotypes (N = 3), and they developed no side effects. Although MTHFR SNP involved in folate metabolism is not related to susceptibility to psoriasis and its severity, SNP could become a predictive index to use MTX safely and effectively in psoriasis treatment.

folic acid

methotrexate

methylenetetrahydrofolate reductase

polymorphism

disease susceptibility to psoriasis