Also known as AIP, are associated with acute attacks only, this type does not exhibit any form of skin manifestations.

AIP is an inherited disease. Very rarely, one encounters cases without a history of the disease in the family, but in most, other members of the family will clearly be shown to carry this disease. Not all people with AIP are related however. Research has shown that many different mutations in the gene for PBGD are possible, each having arisen independently at a different place in the world, but all resulting in AIP. Thus, we find AIP in all countries and all races. The disease is particularly common in Scandinavia and parts of northern Europe, but is certainly not confined to people of European extraction.

Inheritance of AIP

AIP is inherited as an autosomal dominant condition. In simple terms, this means that only one parent need be affected for the children to run the risk of showing the disease. In fact, each child will have a 50% chance of inheriting that disease. Both boys and girls stand an equal chance of inheriting the disease.

Will everyone who inherits the gene show the disease?
Not at all. Only some people who have inherited the disease actually show any signs of it. Of the remainder, some will show biochemical abnormalities (an elevated ALA and PBG in the urine) and yet will never have symptoms. Still others do not even show this biochemical disturbance, though direct testing of the enzyme PBGD will prove that they did indeed inherit the disease. Thus, it is true to say that only a minority of patients carrying AIP are ever troubled by the disease. Most will lead happy, fulfilling and relatively healthy and normal lives.

How Do the Symptoms of AIP Come About?
The accumulation of ALA and PBG may be so marked that levels of these substances become very high indeed. This results in a clinical picture known as the acute attack. It is not known whether the ALA and PBG themselves are directly dangerous to the body, or whether it is some other substance which accumulates with them.