Annet M. Oostveen, Judith G.M. Bergboer, Peter C.M. van de Kerkhof, Patrick L.J.M. Zeeuwen, Elke M.G.J. de Jong, Joost Schalkwijk, Marieke M.B. Seyger
DOI: 10.2340/00015555-1810

This study aims to investigate associations between observed clinical parameters and known genetic risk factors of psoriasis in a well-defined prospective cohort of paediatric patients with plaque psoriasis (n=151). Significant associations were found for paediatric-onset psoriasis with ERAP1 (p=0.002), IL23R (p=0.01), LCE3C_LCE3B-del (p=0.00049) and HLA-C*06 (p=3.15×10–30). Psoriasis severity was associated with the single nucleotide polymorphisms tagging IFIH1 and ERAP1 (p<0.05). An onset before 10 years of age was associated with IL12B (p=0.02). Nail psoriasis was more often seen in HLA-C*06-negative patients (p=0.008). Remarkably, family history is clearly not associated with HLA-C*06 in this specific group. The large proportion of patients with a positive family history in HLA-C*06 negative patients (and the lack of correlation between the two) indicates that other genes, either alone or interaction between two or more genes, may have significant effects on heritability.