$Unique_ID{BRK04130} $Pretitle{} $Title{Porphyria, Erythropoietic Protoporphyria} $Subject{Porphyria Erythropoietic Protoporphyria Porphyria EPP} $Volume{} $Log{} Copyright (C) 1987, 1988, 1990 National Organization for Rare Disorders, Inc. 322: Porphyria, Erythropoietic Protoporphyria ** IMPORTANT ** It is possible the main title of the article (Erythropoietic Protoporphyria) is not the name you expected. Please check the SYNONYMS listing to find the alternate names and disorder subdivisions covered by this article. Synonyms Porphyria EPP General Discussion ** REMINDER ** The information contained in the Rare Disease Database is provided for educational purposes only. It should not be used for diagnostic or treatment purposes. If you wish to obtain more information about this disorder, please contact your personal physician and/or the agencies listed in the "Resources" section of this report. Erythropoietic Protoporphyria (EPP) is inherited as an autosomal dominant trait and is primarily a bone marrow disorder. Ferrochelatase is the deficient enzyme, and there is an accumulation of protoporphyrin in the bone marrow, red blood cells and sometimes in the liver. Excess protoporphyrin is excreted by the liver into the bile, which in turn enters the intestine and is excreted in the feces. There are no urinary abnormalities. The diagnosis is established by finding increased protoporphyrin in the red blood cells, plasma and feces. The Porphyrias are a group of at least seven disorders. The common feature in all porphyrias is the excess accumulation in the body of "porphyrins" or "porphyrin precursors." These are natural chemicals that normally do not accumulate in the body. Precisely which one of these porphyrin chemicals builds up depends upon the type of porphyria that a patient has. Porphyrias can also be classified into two groups: the "hepatic" and "erythropoietic" types. Porphyrins and related substances originate in excess amounts from the liver in the hepatic types, and mostly from the bone marrow in the erythropoietic types. The porphyrias with skin manifestations are sometimes called "cutaneous porphyrias." The "acute porphyrias" are characterized by sudden attacks of pain and other neurological manifestations. These "acute symptoms can be both rapidly-appearing and severe. An individual may be considered in a "latent" condition if he or she has the characteristic enzyme deficiency, but has never developed symptoms. There can be a wide spectrum of severity between the "latent" and "active" cases of any particular type of this disorder. The symptoms and treatments of the different types of porphyrias are not the same. For more information on the other types of porphyria, choose "porphyria" as your search term in the Rare Disease Database. Symptoms In Erythropoietic Protoporphyria, swelling, burning, itching, and redness of the skin may appear during or immediately after exposure to sunlight, including sunlight through window glass. Usually, these symptoms subside in 12 to 24 hours and heal without significant scarring or discoloration of the skin. Occasionally, the skin problems occur only after extended sunlight exposure. The skin lesions may progress to a chronic stage persisting for weeks and healing with a superficial scar. However, blistering and scarring is less common than in other types of "cutaneous" porphyria. Skin manifestations generally begin during childhood. They are more severe in the summer and can recur throughout life. Other manifestations may include gallstones containing protoporphyrin, and occasionally, severe liver complications. The symptoms of porphyria generally arise from effects on the nervous system and/or the skin. Sometimes, the cause of the nervous system symptoms is not clear, and proper diagnosis is delayed. Skin manifestations can include burning, blistering and scarring of sun-exposed areas. Porphyria Cutanea Tarda is the only type of porphyria that can be either acquired or inherited. All other types of Porphyria are caused by genetic factors. Environmental factors such as drugs, chemicals, diet and sun exposure can, depending on the type of the disorder, greatly influence the severity of symptoms. The terms "porphyrin" and "porphyria" are derived from the Greek word "porphyrus," meaning purple. Urine from some porphyria patients may be reddish in color due to the presence of excess porphyrins and related substances, and the urine may darken after being exposed to the light. Causes Erythropoietic Protoporphyria involves an inborn error of metabolism inherited as a dominant trait. (In autosomal dominant disorders, a single abnormal gene, contributed by either parent, "overrides" the normal gene contributed by the other parent causing disease. Individuals with one affected parent have a 50% chance of inheriting the disorder. Males and females will be affected in equal numbers.) Environmental factors may include drugs, chemicals, diet and sun exposure. Depending on the type of porphyria, these factors can greatly influence the severity of symptoms. Affected Population Erythropoietic Protoporphyria usually begins in childhood. The intensity of symptoms may increase in summer and fall. This disorder may affect males and females in equal numbers. Related Disorders The Porphyrias are a group of related disorders. For more information on each of the following types of the disease, choose "porphyria" as your search term in the Rare Disease Database. ALA-D Porphyria is a recently-described form of acute porphyria inherited as an autosomal recessive trait. It is apparently extremely rare. There is a deficiency of the enzyme delta-aminolevulinic acid dehydratase (ALA-D) and increased excretion of ALA in the urine of patients with this type of porphyria. Acute Intermittent Porphyria is a hereditary, possibly metabolic, usually asymptomatic disorder (latent). It may possibly be provoked into active disease by the administration of certain drugs, notably barbiturates, sulfonamides, and estrogenic compounds. Congenital Erythropoietic Porphyria (CEP) is a hereditary disorder due to an inborn error of metabolism, and manifested in infancy. Faulty conversion of the enzyme PBG to uroporphyrinogen in erythroid cells of bone marrow, red blood cells, plasma, urine and feces leads to this type of Porphyria. Increased porphyrins also may be found in plasma, urine, feces, teeth and bones. Porphyria Cutanea Tarda (PCT) can be either an acquired or inherited type of Porphyria. It may become acute due to exposure to chronic alcoholism, barbiturates or other chemicals, cirrhosis of the liver, or a hepatic tumor. It may also stem from a nutritional disorder. Hereditary Coproporphyria (HCP) is a latent type of Porphyria with attacks usually precipitated by exposure to drugs such as barbiturates, tranquilizers, anticonvulsants, and estrogens. Variegate Porphyria (VP) is a hereditary type of Porphyria due to an inborn error of metabolism. Precipitating or aggravating factors may include exposure to barbiturates, sulfonamides, general anesthetics, excessive amounts of ethanol, and estrogens. Therapies: Standard Treatment for Erythropoietic Protoporphyria (EPP) with the orphan drug Beta Carotene often improves sunlight tolerance, but does not lower porphyrin levels. Cholestyramine may lower porphyrin levels in some patients. Some carriers of the gene for this disease have no symptoms, and may occasionally have normal porphyrin levels. Patients with EPP may develop liver abnormalities, due to excess deposits of protoporphyrin in that organ. Total avoidance of certain drugs including barbiturates, sulfonamides, and estrogen compounds is suggested. It is important to note that a patient with EPP never develops any other types of porphyria, although some treatments may be similar. Avoidance of alcohol is also strongly suggested as alcohol seems to increase severity of photosensitivity in this disorder. The orphan drug Hematin (an intravenous drug) is very potent in suppressing acute attacks of the disease. It is usually given only after a trial of glucose therapy. Attention should be given to salt and water balance during treatment. Many types of drugs such as aspirin and certain antibiotics are believed to be safe in patients with some types of porphyria. Recommendations about drugs for certain types of the disorder are based on experience with the porphyria patients in whom attacks have been caused by drugs and by tests in animals. Since many commonly used drugs have not been tested, they should be avoided if at all possible. If a question of drug safety arises, a physician or medical center specializing in porphyria should be contacted. A list of these institutions may be procured from the American Porphyria Foundation (see Resources). Pregnancy is tolerated much better than was formerly believed. Many patients have a few reservations about family planning. For those who do, genetic counseling may be useful. Wearing a Medic Alert bracelet is advisable in patients who have had attacks, but is probably not warranted in most latent cases. Therapies: Investigational New treatments for several types of porphyria are under investigation. For the most updated information on research, please contact the organizations listed in the Resources section. This disease entry is based upon medical information available through March 1990. Since NORD's resources are limited, it is not possible to keep every entry in the Rare Disease Database completely current and accurate. Please check with the agencies listed in the Resources section for the most current information about this disorder. Resources For more information on Erythropoietic Protoporphyria, please contact: National Organization for Rare Disorders (NORD) P.O. Box 8923 New Fairfield, CT 06812-1783 (203) 746-6518 American Porphyria Foundation P.O. Box 22712 Houston, TX 77227 (713) 266-9617 Porphyria Support Group 4 Eve Road Leytonstone, London, England E11 3JE Tel: 01-519-7868 National Digestive Diseases Information Clearinghouse Box NDDIC Bethesda, MD 20892 (301) 468-2344 For information on genetics and genetic counseling referrals, please contact: March of Dimes Birth Defects Foundation 1275 Mamaroneck Avenue White Plains, NY 10605 (914) 428-7100 Alliance of Genetic Support Groups 35 Wisconsin Circle, Suite 440 Chevy Chase, MD 20815 (800) 336-GENE (301) 652-5553 References American Porphyria Foundation brochure, "Common Questions About Porphyria."