Genetics of psoriasis

Psoriasis is a chronic inflammatory disease of unknown cause with variable clinical expression. In the absence of clearly identified psoriasis autoantigen, there is debate as to whether it can be considered an autoimmune disease. However, considerable evidence obtained from twin studies, demographic studies, and genome‐wide scans performed in several extended patient cohorts and carefully selected psoriasis pedigrees, clearly established that genetics is a key component in the development of psoriasis. The common thought is that psoriasis has a multifactorial mode of inheritance, and that in order for an individual to develop clinical lesions, several psoriasis‐susceptibility genes have to interact together and with various environmental factors. This article reviews some past and current findings on the genetics of psoriasis.