Wednesday, April 26, 2017

Learn all about VP Variegate Porphyria by the NIH







Other Names:
 
Porphyria variegate; VP; Porphyria, South African type; See More


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Variegate porphyria is a form of hepatic porphyria most common in the white South African population. This autosomal dominant disorder may produce acute attacks (as in acute intermittent porphyria) as well as skin photosensitivity.[1][2] The condition is caused by mutations in the PPOX gene which lead to deficiency of the enzyme protoporphyrinogen oxidase.[3] Acute attacks are managed and may be prevented as in acute intermittent porphyria.[1]
Last updated: 7/19/2010

Episodes of acute variegate porphyria can cause abdominal pain, vomiting, constipation, and diarrhea. During an episode, a person may also experience muscle weakness, seizures, fever, and mental changes such as anxiety and hallucinations. Individuals with variegate porphyria may also develop cutaneous symptoms, including skin photosensitivity.[3]
Last updated: 7/19/2010
The Human Phenotype Ontology (HPO) provides the following list of features that have been reported in people with this condition. Much of the information in the HPO comes from Orphanet, a European rare disease database. If available, the list includes a rough estimate of how common a feature is (its frequency). Frequencies are based on a specific study and may not be representative of all studies. You can use the MedlinePlus Medical Dictionary for definitions of the terms below.
Signs and SymptomsApproximate number of patients (when available)Help
Hypopigmented skin patchesVery frequent
(present in 80%-99% of cases)
ScarringVery frequent
(present in 80%-99% of cases)
Thin skinVery frequent
(present in 80%-99% of cases)
Abnormal blistering of the skinFrequent
(present in 30%-79% of cases)
Cutaneous photosensitivityFrequent
(present in 30%-79% of cases)
Abdominal painOccasional
(present in 5%-29% of cases)
AnxietyOccasional
(present in 5%-29% of cases)
ConfusionOccasional
(present in 5%-29% of cases)
ConstipationOccasional
(present in 5%-29% of cases)
DepressionOccasional
(present in 5%-29% of cases)

Last updated: 3/10/2017

Variegate porphyria is caused by mutations in the PPOX gene.[3] Mutations in the PPOX gene reduce the activity of protoporphyrinogen oxidase, allowing compounds called porphyrin precursors to build up in the body. These compounds are formed during the normal process of heme production, but reduced activity of protoporphyrinogen oxidase allows them to accumulate to toxic levels. More than 130 mutations in the PPOX gene have been identified in people with variegate porphyria. A particular PPOX gene mutation is found in about 95 percent of South African families with the disorder.[4]
Nongenetic factors such as certain drugs, alcohol, dieting, as well as other genetic factors that have not been identified, also contribute to the characteristic features of variegate porphyria.[4]
Last updated: 7/19/2010

Variegate porphyria is inherited in an autosomal dominant manner, which means one copy of the gene in each cell is mutated. This single mutation is sufficient to reduce the activity of an enzyme needed for heme production, which increases the risk of developing signs and symptoms of porphyria.[1][3]
Last updated: 7/19/2010

The diagnosis of variegate porphyria is made by finding excess coproporphyrin in urine and both coproporphyrin and protoporphyrin in feces.[1][2] The most sensitive screening test is probably a plasma porphyrin assay.[1]
Last updated: 7/19/2010

Testing Resources

  • The Genetic Testing Registry (GTR) provides information about the genetic tests for this condition. The intended audience for the GTR is health care providers and researchers. Patients and consumers with specific questions about a genetic test should contact a health care provider or a genetics professional.

    Acute attacks are managed and may be prevented as in acute intermittent porphyria.[1][2] Hospitalization is often necessary for acute attacks. Medications for pain, nausea and vomiting, and close observation are generally required. A high intake of glucose or other carbohydrates can help suppress disease activity and can be given by vein or by mouth. Intravenous heme therapy is more potent in suppressing disease activity. It can be started after a trial of glucose therapy. However, the response to heme therapy is best if started early in an attack. Heme must be administered by vein. Panhematin is the only commercially available heme therapy for treatment and prevention of acute porphyric attacks in the United States. Heme arginate, which is marketed in some other countries, is another preparation of heme for intravenous administration.[5]
    Last updated: 7/19/2010

    Management Guidelines

    • Orphanet Emergency Guidelines is an article which is expert-authored and peer-reviewed that is intended to guide health care professionals in emergency situations involving this condition.  
    • The American Porphyria Foundation offers a document that includes information about porphyria, types, testing, and treatment with Panhematin®.  Click the "document" link above to view these guidelines.

      Research helps us better understand diseases and can lead to advances in diagnosis and treatment. This section provides resources to help you learn about medical research and ways to get involved.

      Patient Registry

      • The Porphyrias Consortium is a team of doctors, nurses, research coordinators, and research labs throughout the U.S., working together to improve the lives of people with this condition through research. The Porphyrias Consortium has a registry for patients who wish to be contacted about clinical research opportunities. 

        For more information on the registry see: http://rarediseasesnetwork.epi.usf.edu/registry/index.htm

        Nonprofit support and advocacy groups bring together patients, families, medical professionals, and researchers. These groups often raise awareness, provide support, and develop patient-centered information. Many are the driving force behind research for better treatments and possible cures. They can direct people to research, resources, and services. Many groups also have experts who serve as medical advisors. Visit their website or contact them to learn about the services they offer. Inclusion on this list is not an endorsement by GARD.

        Organizations Supporting this Disease

          Social Networking Websites

          • RareConnect has an online community for patients and families with this condition so they can connect with others and share their experiences living with a rare disease. The project is a joint collaboration between EURORDIS (European Rare Disease Organisation) and NORD (National Organization for Rare Disorders).

            Organizations Providing General Support


              Living with a genetic or rare disease can impact the daily lives of patients and families. These resources can help families navigate various aspects of living with a rare disease.

              Genetics Resources

                Financial Resources

                • The HealthWell Foundation provides financial assistance for underinsured patients living with chronic and life-altering conditions. They offer help with drug copayments, deductibles, and health insurance premiums for patients with specific diseases. The disease fund status can change over time, so you may need to check back if funds are not currently available.

                  These resources provide more information about this condition or associated symptoms. The in-depth resources contain medical and scientific language that may be hard to understand. You may want to review these resources with a medical professional.

                  Where to Start

                  • Genetics Home Reference (GHR) contains information on Variegate porphyria. This website is maintained by the National Library of Medicine.
                  • MedlinePlus was designed by the National Library of Medicine to help you research your health questions, and it provides more information about this topic. 
                  • The National Digestive Diseases Information Clearinghouse (NDDIC), part of the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), offers information on this condition. Click on the link to view information on this topic.
                  • The National Organization for Rare Disorders (NORD) has a report for patients and families about this condition. NORD is a patient advocacy organization for individuals with rare diseases and the organizations that serve them.

                    In-Depth Information

                    • Medscape Reference provides information on this topic. You may need to register to view the medical textbook, but registration is free.
                    • The Monarch Initiative brings together data about this condition from humans and other species to help physicians and biomedical researchers. Monarch’s tools are designed to make it easier to compare the signs and symptoms (phenotypes) of different diseases and discover common features. This initiative is a collaboration between several academic institutions across the world and is funded by the National Institutes of Health. Visit the website to explore the biology of this condition.
                    • Online Mendelian Inheritance in Man (OMIM) is a catalog of human genes and genetic disorders. Each entry has a summary of related medical articles. It is meant for health care professionals and researchers. OMIM is maintained by Johns Hopkins University School of Medicine. 
                    • Orphanet is a European reference portal for information on rare diseases and orphan drugs. Access to this database is free of charge.
                    • PubMed is a searchable database of medical literature and lists journal articles that discuss Variegate porphyria. Click on the link to view a sample search on this topic.


                      The following diseases are related to Variegate porphyria. If you have a question about any of these diseases, you can contact GARD.

                      Questions sent to GARD may be posted here if the information could be helpful to others. We remove all identifying information when posting a question to protect your privacy. If you do not want your question posted, please let us know. Submit a new question
                      • I have just had my DNA report returned to find that I am a carrier of variegate porphyia as is my daughter. We both are asymptomatic. I am not South African Dutch. How many second generation and now third generation Americans are diagnosed yearly? If I have never had symptoms (age 65), will I have symptoms?See answer


                      1. Variegate Porphyria (VP). American Porphyria Foundation. 2010; http://www.porphyriafoundation.com/about-porphyria/types-of-porphyria/VP. Accessed 7/19/2010.
                      2. Porphyria, Variegate. National Organization for Rare Disorders (NORD). 2001; http://www.rarediseases.org/search/rdbdetail_abstract.html?disname=Porphyria%2C%20Variegate. Accessed 7/19/2010.
                      3. Porphyria. Genetics Home Reference (GHR). 2009; http://ghr.nlm.nih.gov/condition=porphyria. Accessed 7/19/2010.
                      4. PPOX. Genetics Home Reference (GHR). 2009; http://ghr.nlm.nih.gov/gene/PPOX. Accessed 7/19/2010.
                      5. Acute Intermittent Porphyria (AIP). American Porphyria Foundation. 2010; http://www.porphyriafoundation.com/about-porphyria/types-of-porphyria/AIP. Accessed 7/19/2010.

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