Mutation analysis of the IL36RN gene in Chinese patients with generalized pustular psoriasis with/without psoriasis vulgaris

• Six IL36RN variants were found in 29 GPP patients, 12 PV cases and 6 controls.
• The variants’ frequencies were different between GPP and PV groups.
• There were also significant differences between GPP alone and GPP with PV groups.
• Demonstrated that GPP and PV are distinct subtypes of psoriasis on the etiology.
• GPP alone may be regarded as an especial entities of GPP different from GPP with PV.

BackgroundGeneralized pustular psoriasis (GPP) is a rare type of psoriasis with potentially life-threatening implications. Mutations in IL36RN gene have been suggested to be causative or predisposing factors for GPP.ObjectiveTo evaluate the genetic heterogeneity of GPP, PV and GPP alone, GPP with PV.MethodsWe performed a sanger sequencing identify IL36RN mutations in 62 Chinese Han patients with sporadic GPP, including 17 GPP without psoriasis vulgaris (PV) (GPP alone) cases vs. 45 GPP with preceding, later or accompanied by PV (GPP with PV) cases; 16 patients with pediatric-onset GPP (PGPP) vs. 46 adult-onset GPP (AGPP). We included 96 healthy controls and 174 sporadic patients with PV.ResutsWe found 2 new variants and 4 known IL36RN variants in 29 GPP patients, 18 individuals carried recessive (homozygous/compound heterozygous) alleles and 11 cases harbored a single heterozygous change. Twelve PV patients and six controls harbored a single heterozygous for three out of the six variants.Significant differences were observed between GPP and PV groups, GPP alone and GPP with PV groups when compared frequencies of IL36RN variants, but we did not found association between PGPP and AGPP groups.ConclusionOur study provided more evidence that GPP and PV are distinct subtypes of psoriasis caused by different pathogenesis, and GPP alone could be regarded as an especial entities of GPP which is different from GPP with PV on the etiology.