National Organization for Rare Disorders, Inc.
It is possible that the main title of the report Porphyria, Variegate is not the name you expected. Please check the synonyms listing to find the alternate name(s) and disorder subdivision(s) covered by this report.
Synonyms Back to top
- porphyria variegata
Disorder Subdivisions Back to top
General Discussion Back to top
Variegate porphyria is a rare genetic metabolic disorder characterized by deficient function of the enzyme protoporphyrinogen oxidase (PPO or PPOX). This deficiency is caused by heterozygous mutations in the PPOX gene, and leads to the accumulation of certain chemicals called porphyrins and porphyrin precursors in the body, which, in turn, can potentially result in a variety of symptoms. Specific symptoms can vary greatly from one person to another. Some affected individuals present with skin symptoms, some with neurological symptoms and some with both. Blistering and fragility of sun-exposed skin are the most common skin (cutaneous) symptoms. Common neurological symptoms include abdominal pain, nausea, vomiting, constipation, extremity pain and weakness, anxiety, restlessness and convulsions. Many different PPOX mutations have been identified in different families with variegate porphyria. The genetic mutation in a family is inherited as an autosomal dominant trait, but many individuals who inherit a PPOX mutation do not develop any symptoms (asymptomatic).
Variegate porphyria is one of a group of disorders known as the porphyrias. The porphyrias are characterized by abnormally high levels of porphyrins or porphyrin precursors in the body. Each porphyria is due to a deficiency of a differnt enzyme. There are eight enzymes in the pathway for making heme, which is a part of hemoglobin and other hemoproteins. There are at least seven types of porphyria. The symptoms associated with the various types of porphyria differ, depending upon the specific enzyme that is deficient. It is important to note that people who have one type of porphyria do not develop any of the other types. Porphyrias are generally classified into two groups: the "hepatic" and "erythropoietic" types. Porphyrins and porphyrin precorsors originate in excess amounts from the liver in the hepatic types, and mostly from the bone marrow in the erythropoietic types. Variegate porphyria is a hepatic form of porphyria.
Protoporphyrinogen and coproporphyrinogen accumulate in the liver in variegate porphyria because PPOX is deficient, and becomes oxidized to protoporphyrin and coproporphyrin, which are transported in the blood plasma and cause the skin to be sensitive to sunlight. The neurological symptoms are associated with accumulation of porphyrin precursors, namely delta-aminolevulinic acid (ALA) and porphobilinogen (PBG).
Resources Back to top
CLIMB (Children Living with Inherited Metabolic Diseases)
176 Nantwich Road
Crewe, CW2 6BG
American Porphyria Foundation
4900 Woodway, Suite 780
Houston, TX 77056-1837
NIH/National Institute of Diabetes, Digestive & Kidney Diseases
Office of Communications & Public Liaison
Bldg 31, Rm 9A06
31 Center Drive, MSC 2560
Bethesda, MD 20892-2560
MedicAlert Foundation International
2323 Colorado Avenue
Turlock, CA 95382
British Porphyria Association
136 Devonshire Rd
Durham City, DH1 2BL
Genetic and Rare Diseases (GARD) Information Center
PO Box 8126
Gaithersburg, MD 20898-8126
For a Complete Report Back to top
This is an abstract of a report from the National Organization for Rare Disorders (NORD). A copy of the complete report can be downloaded free from the NORD website for registered users. The complete report contains additional information including symptoms, causes, affected population, related disorders, standard and investigational therapies (if available), and references from medical literature. For a full-text version of this topic, go to www.rarediseases.org and click on Rare Disease Database under "Rare Disease Information".
The information provided in this report is not intended for diagnostic purposes. It is provided for informational purposes only. NORD recommends that affected individuals seek the advice or counsel of their own personal physicians.
It is possible that the title of this topic is not the name you selected. Please check the Synonyms listing to find the alternate name(s) and Disorder Subdivision(s) covered by this report
This disease entry is based upon medical information available through the date at the end of the topic. 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.
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Last Updated: 1/30/2013
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