Simultaneous Onset of Psoriasis Vulgaris in Monozygotic Twins

Excerpt

An accumulation of psoriasis within families was first reported in 1801.[1] Twin studies later demonstrated that the concordance rate in monozygotic twins is significantly higher than in dizygotic twins, supporting the inherited nature of psoriasis vulgaris. Besides genetics, other factors seem to be responsible for manifestation as the concordance in monozygotic twins is not 100%. In 1972, Russel et al.[2] were the first group to report a disease association to several histocompatibility (HLA)-antigens in psoriasis. Today, a multifactorial state of inheritance is favored and in addition to the major histocompatibility complex (MHC), several candidate or susceptibility genes for psoriasis have been proposed.[3] …