British 
Porphyrias
Information for patients & their families
FAQs on the acute porphyrias
TABLE OF CONTENTS
How many types of porphyria are there?
What is porphyria?
Porphyria is a fairly uncommon condition. There are seven types of Porphyria. Most of these are inherited but some may be acquired.
All living things including healthy people produce prophyrins. Our bodies convert two simple substances, ( ALA ) and (PBG) known as porphyrin precursors, into more complicated substances called porphyrins. These are then converted from one type of porphyrin to the next, in a kind of chain reaction, or pathway, and with the help of iron form Haem. Heam is a red organic compound found in haemoglobin, the colouring matter of the red corpuscles of the blood.
A special protein known as an enzyme completes each step on the pathway to produce Haem. In each type of porphyria, a specific enzyme is deficient, and this is why prophyrins accumulate.
How many types of porphyria are there?
Altogether there are seven main types of porphyria, four are acute porphyrias. Most of the others affect only the skin. All seven types are described below. They are called porphyrias because they cause accumulation of chemicals called porphyrins (purple-red pigments named from the Greek for purple) or the simpler chemicals that are used up by the body to make porphyrins. When porphyrins accumulate in the skin, it becomes very sensitive to sunlight and this causes the skin symptoms of porphyria. Accumulation of the simpler chemicals in the liver leads to acute attacks of porphyria. Porphyrins are important in the body because they combine with iron to form haem, a red pigment which has the vital function of enabling the body's cells to use oxygen.
The acute porphyrias are metabolic disorders that affect biochemical processes. They do not cause blood disease or liver disease. There is more information on these on the "acute poprhyrias" page
It is important for you to find out which type of porphyria you have because the inherited abnormality and symptoms are different in each one.
Acute Intermittent Porphyria (AIP)
AIP is an INHERITED condition. It is passed on from generation to generation. This means that it may be passed on from parents to their children. This occurs so that half of an affected parent's children are likely to be affected. Both boys and girls stand an equal chance of being affected. The condition cannot be cured. You cannot be blamed for passing it on to your children.
Those with AIP are at risk of developing an acute attack, as well as many other possible, varied symptoms. Symptoms and their severity will vary from patient to patient, and some people will be totally asymptomatic (without any symptoms) throughout their lives.
For more information on the acute porphyrias, see the acute porphyria FAQs
Variegate Porphyria (VP)
Like AIP, VP is always an inherited conditions. People with VP are prone to skin problems and to the acute attack.
In variegate porphyria, the skin changes and attacks of acute porphyria may not occur at the same time.
Again, see the acute porphyria FAQs
Hereditary Coproporphyria (HCP)
This too is always an inherited condition. People with HCP are prone to acute attacks, and can have skin problems during an acute attack.
For more information, see the acute porphyria FAQs
Aminolevulinate dehydratase deficiency porphyria (ADP)
ADP is an extremely rare condition and in the few cases described is similar to AIP
Porphyria Cutanea Tarda (PCT)
Very rarely, PCT is inherited from one's parents in the manner described for AIP,VP & HC. Most people with PCT did not inherit the disorder and will not pass it on to their children. Here, PCT is secondary to another condition. It may arise in some people because of taking too much alcohol.
Commonly, such people have additionally an excess of iron in their bodies. It may also follow the use of some drugs, such as the oestrogen used in the pill or for relief of symptoms of the menopause and after exposure to certain chemicals. People with PCT commonly develop skin problems. They will NEVER suffer an acute attack. Drugs do not hold the same danger for them as they do for people with AIP or VP, although they should avoid alcohol.
Erythropoietic Protoporphyria (EPP)
This is a less common form of porphyria. Like AIP VP & HC it is an inherited disorder that is passed on from parents to their children. People with EPP suffer skin problems, but do not develop acute attacks nor are drugs of concern. However the liver may become involved in later years.
Congenital Porphyria (CP)
This is the rarest of the porphyrias. It is primarily a skin condition and uniquely is inherited as a recessive condition. That means that both parents are asymptomatic carriers.