Mutation analysis of the IL36RN gene in Japanese patients with palmoplantar pustulosis

Abstract

The IL36RN gene encodes the interleukin 36-receptor antagonist (IL-36 Ra), which regulates downstream inflammatory signaling provoked by interleukin-36 (α, β, and γ). Some of its mutations leading to deficiency of the IL-36Ra have been reported as the major cause of generalized pustular psoriasis (GPP) without psoriasis vulgaris. The mutation p.L27P caused by a point mutation c.213T>C on the second coding exon in IL36RN gene was originally reported to be associated with cases of familial GPP. Afterward, additional several mutations in IL36RN gene were reported. Recently, it has been reported that similar mutations were detected also in the patients with GPP-related diseases including palmoplantar pustulosis (PPP), acrodermatitis continua of Hallopeau, and acute generalized exanthematous pustulosis. Regarding PPP, which is considered as the localized type of pustular psoriasis, the mutation in IL36RN gene such as homozygous or heterozygous p.S113L has been identified only in very small numbers of patients. In addition, no sizable researches on Japanese patients with PPP have ever been conducted. In this study, we aim to analyze the IL36RN gene mutation in large-scale Japanese patients with PPP.