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$Unique_ID{BRK04129}
$Pretitle{}
$Title{Porphyria, Congenital Erythropoietic}
$Subject{Porphyria Congenital Erythropoietic Congenital Porphyria Guenther
Porphyria CEP}
$Volume{}
$Log{}
Copyright (C) 1987, 1988, 1990 National Organization for Rare Disorders, Inc.
319:
Porphyria, Congenital Erythropoietic
** IMPORTANT **
It is possible the main title of the article (Congenital Erythropoietic
Porphyria) is not the name you expected. Please check the SYNONYMS listing
to find the alternate names and disorder subdivisions covered by this
article.
Synonyms
Congenital Porphyria
Guenther Porphyria
CEP
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.
Congenital Erythropoietic Porphyria (CEP) is extremely rare and is
inherited through an autosomal recessive trait. It is also known as
Guenther Porphyria. The deficient enzyme is uroporphyrinogen III
cosynthase. As is characteristic of the erythropoietic porphyrias, symptoms
usually begin during infancy. CEP is manifested by markedly increased levels
of porphyrins in bone marrow, red blood cells, plasma, urine and feces.
Porphyrins are also deposited in the teeth and bones.
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 those 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
Skin photosensitivity, a symptom of Congenital Erythropoietic Porphyria, may
be extreme and lead to blistering, severe scarring and increased hair
growth. Bacteria may infect the damaged skin. Facial features and fingers
may be lost through this process over time. Red blood cells have a
shortened life-span, and anemia often results. Synthesis of heme and
hemoglobin, substances important to many body functions that are found in
the bone marrow, red blood cells and the liver, is actually increased to
compensate for the shortened red blood cell survival.
The symptoms of porphyria generally arise from effects on the nervous
system and/or the skin. Sometimes, the effects on the nervous system are
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 porphyria, 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
Congenital Erythropoietic Porphyria (CEP) is a hereditary non-x-linked trait
disorder. A faulty conversion of PBG to uroporphyrinogen in the erythroid
cells of the bone marrow is the basic inborn metabolic error.
Environmental factors that may aggravate the symptoms include drugs,
chemicals, diet, and sun exposure. Depending on the type of porphyria,
these factors can greatly influence the severity of symptoms.
Because all porphyrias are uncommon, it is very unlikely that more than
one type will occur in the same family, or that someone with one type of
porphyria will go on to develop another.
Affected Population
The onset of Congenital Erythropoietic Porphyria is in early infancy and is
primarily a rare childhood form of porphyria. It affects 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 dominant disorder. A
latent form of porphyria, it may possibly be provoked into active disease by
the administration of certain drugs, notably barbiturates, sulfonamides, and
estrogen compounds.
Porphyria Cutanea Tarda (PCT) can be either an acquired or inherited
type of Porphyria. It may become acute due to exposure to chronic alcohol
intake, 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 similar to
Acute Intermittent Porphyria, although usually less severe. This disorder
is due to an enzyme deficiency. Some patients may develop skin
photosensitivity. Attacks are usually precipitated by exposure to drugs
such as barbiturates, tranquilizers, anticonvulsants, and estrogens.
Precautions and treatment for acute attacks are as described for AIP.
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.
Erythropoietic Protoporphyria (EPP) is a hereditary type of Porphyria
marked by an accumulation of protoporphyrin in the bone marrow, red blood
cells and sometimes 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 red blood cells, plasma
and feces.
Therapies: Standard
The orphan drug Hematin (an intravenous drug) is very potent in suppressing
acute attacks of the Congenital Erythropoietic Porphyria. 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 it 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 Congenital Erythropoietic Porphyria, 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) 468-6344
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."