Polymorphisms Associated with Age at Onset in Patients with Moderate-to-Severe Plaque Psoriasis
Psoriasis is a chronic skin disease in which genetics play a major role. Although many genome-wide association studies have been performed in psoriasis, knowledge of the age at onset remains limited. Therefore, we analyzed 173 single-nucleotide polymorphisms in genes associated with psoriasis and other autoimmune diseases in patients with moderate-to-severe plaque psoriasis type I (early-onset, <40 years) or type II (late-onset, ≥40 years) and healthy controls. Moreover, we performed a comparison between patients with type I psoriasis and patients with type II psoriasis. Our comparison of a stratified population with type I psoriasisn=155and healthy controlsN=197is the first to reveal a relationship between theCLMN,FBXL19,CCL4L,C17orf51,TYK2,IL13,SLC22A4,CDKAL1, andHLA-B/MICAgenes. When we compared type I psoriasis with type II psoriasisN=36, we found a significant association between age at onset and the genesPSORS6,TNF-α,FCGR2A,TNFR1,CD226,HLA-C,TNFAIP3, andCCHCR1. Moreover, we replicated the association between rs12191877 (HLA-C) and type I psoriasis and between type I and type II psoriasis. Our findings highlight the role of genetics in age of onset of psoriasis.