Strictly speaking psoriasis is an inherited disease. However, it is not the disease itself, which is inherited in a particular form, but rather the predisposition to its development. The relevant genetic information is probably distributed at various sites on chromosome number 6. This means that if there are people with psoriasis among your relatives, then you have an increased risk of suffering from the disease yourself. If one parent is affected, the children have a 25% probability of developing psoriasis, if both parents are affected the figure is as much as 75%. But these are just figures and practically you should not get worried over this thought, as then if we delve deeper we are all carrying various genes that can result in disease later on.