Etiopathogenisis 1. Theory of heredity O Family positive of psoriasis is 4% 11932% in china O Concordance rate in twins monozygotic twins> binovular twins High frequency in HLA-Al, B17, CW6,DR7 a multifactorial inheritance diseaseEtiopathogenisis 1.Theory of heredity ⚫ Family positive of psoriasis is 4~91％, 11.9~32% in china ⚫ Concordance rate in twins: monozygotic twins> binovular twins ⚫ High frequency in HLA-A1,B17,Cw6,DR7, a multifactorial inheritance disease