United Porphyrias Association
www.porphyria.orgThe United Porphyrias Association supports the patient and healthcare professional communities with diagnosis, management, and treatment of the porphryias.
What is Porphyria?
The porphyrias are a group of rare, genetic disorders. People living with a porphyria have changes to certain genes, called mutations, which affect their body’s ability to regulate itself.
In the porphyrias, these mutations are in the genes involved in a certain chemical pathway, called the heme biosynthetic pathway. Heme is a compound that the body needs to make hemoglobin and there are several steps to make this compound in the body. Each type of porphyria is caused by a defect in a specific enzyme in the heme biosynthetic pathway. Without these enzymes working properly, the body is not able to finish making heme and it causes a buildup of other compounds, called porphyrins. It is the buildup of different types of porphyrins that causes the different types of porphyria and associated symptoms.
Most commonly the porphyrias are divided into the “acute hepatic porphyrias” (AHPs) and “cutaneous porphyrias,” depending on the primary symptoms.
AHPs, including acute intermittent porphyria (AIP), hereditary coproporphyria (HCP), variegate porphyria (VP), and ALA-dehydratase deficiency porphyria (ALD) typically present with sudden attacks of severe stomach pain, among other symptoms, which last for several days; VP and HCP may also have skin symptoms of blistering after sun exposure.
The cutaneous porphyrias present with blistering and scarring of the skin, pain, and/or redness and swelling in sun-exposed areas.
The porphyrias may also be classified as “hepatic” or “erythropoietic,” depending on the organ where the porphyrins accumulate. This includes the liver for the acute hepatic porphyrias (AIP, HCP, VP, porphyria cutanea tarda (PCT), and hepatoerythropoietic porphyria (HEP) or the bone marrow for the erythropoietic porphyrias (congenital erythropoietic porphyria (CEP), erythropoietic protoporphyria (EPP), and X-linked protoporphyria (XLP).
What are the types of Porphyria?
Acute Hepatic Porphyrias (AHP)
The Acute Hepatic Porphyrias (AHP) are porphyrias where the main enzyme defects are in the liver (hepatic). They typically present with sudden attacks of severe stomach pain, among other symptoms, which last for several days; VP and HCP may also have skin symptoms of blistering after sun exposure.
- Acute Intermittent Porphyria (AIP)
- Variegate Porphyria (VP)
- Hereditary Coproporphyria (HCP)
- ALAD-Deficiency Porphyria (ADP)
Cutaneous Porphyrias
Cutaneous Erythropoietic Porphyrias:
The cutaneous erythropoietic porphyrias are porphyrias that involve various skin symptoms and the main organ involved is the bone marrow. These typically present with blistering and scarring of the skin, pain, and/or redness and swelling in sun-exposed areas.
- Erythropoietic Protoporphyria (EPP) and X-Linked Porphyria (XLP)
- Congenital Erythropoietic Porphyria (CEP)
Cutaneous Hepatic Porphyrias:
The cutaneous hepatic porphyrias are porphyrias that involve various skin symptoms and the main organ involved is the liver. These do not have acute symptoms like the AHPs. They typically present with blistering and scarring of the skin.
- Porphyria Cutanea Tarda (PCT)
- Hepatoerythropoietic Porphyria (HEP)
How is Porphyria Diagnosed?
All porphyria diagnoses are confirmed by biochemical testing. “Clinical diagnoses” without positive biochemical results are not considered diagnostic of porphyria.
First Line Testing:
Biochemical testing, or blood and urine tests, are the first ones that should be done when a type of porphyria is suspected. The specific biochemical tests depend on the symptoms. For all the first line tests the results will be very high if someone has porphyria. Small increases in these tests are generally not diagnostic.
- Acute attack symptoms (i.e. abdominal pain, nausea, vomiting, other pain, etc.) suggestive of an acute porphyria —a urine porphobilinogen (PBG) test, this is different than a test looking for urine total porphyrins.
- Blistering skin symptoms suggestive of PCT, CEP, HEP, VP, or HCP—a blood test called plasma total porphyrins, and a urine total porphyrins test.
- Non-blistering skin symptoms suggestive of EPP or XLP—the blood tests plasma total porphyrins and erythrocyte protoporphyrins.
Making Sure the Tests are Done Properly:
Most of these tests can be done properly at any laboratory. Only erythrocyte protoporphyrin testing should be done at specific labs.
These biochemical tests are sensitive to being in sunlight for extended periods of time, special brown containers are generally used when collecting the samples.
Genetic Testing:
Each type of porphyria (with exception of Sporadic PCT) is caused by a mutation, or change, in the genetic material that codes for a specific enzyme in the heme pathway. This testing is done on a blood, saliva, or mouth swab sample, generally after the biochemical testing has been done in someone who was recently diagnosed, or in family members of someone with a porphyria.
The different genes that cause the porphyrias are:
Type of Porphyria Gene
ALA-Dehydratase Porphyria (ADP) ALAD
Acute Intermittent Porphyria (AIP) HMBS
Congenital Erythropoietic Porphyria (CEP) UROS
Porphyria Cutanea Tarda (PCT), familial form UROD
Hepatoerythropoietic Porphyria (HEP) UROD
Hereditary Coproporphyria (HCP) CPOX
Variegate Porphyria (VP) PPOX
Erythropoietic Protoporphyria (EPP) FECH
X-linked Protoporphyria (XLP) ALAS2
A very small number of people who have a biochemical diagnosis of porphyria may not have a gene change found.
What are the treatment options for Porphyria?
How do I Connect with a Porphyria Specialist?
The Scientific Advisory Board of the UPA is comprised of the foremost porphyria experts in the US. If you require specialist guidance, UPA will be happy to assist in connecting you to a porphyria specialist center for support. Please contact UPA at info@porphyria.org or call 1-800-868-1292.
Where can I learn more about Porphyria?
The United Porphryias Association is devoted to the porphyrias. UPA Is committed to improving the quality of life of the porphyria patient community and is relentlessly focused on advancing disease awareness, research, and therapies in all the porphyrias. The vision of UPA is a world where patients are free from the pain and challenges of porphyria.
For more information:
Visit the United Porphyrias Association website:
www.porphyria.org
Or contact us at Email: info@porphyria.org
Phone: 888-866-1292
The United Porphyrias Association is a 501(c)(3) nonprofit organization supported by tax-deductible donations.
