National Center for Advancing and Translational Sciences Genetic and Rare Diseases Information Center, a program of the National Center for Advancing and Translational Sciences

Porphyria

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I would like to be tested for porphyria. How is this condition diagnosed? Is genetic testing available?

The following information may help to address your question:


What is porphyria?

Porphyrias are a group of blood conditions caused by a lack of an enzyme in the body that makes heme, an important molecule that carries oxygen throughout the body and is vital for all of the body’s organs. Major types include ALAD deficiency porphyria, acute intermittent porphyria, congenital erythropoietic porphyria, erythropoietic protoporphyria, hepatoerythropoietic porphyria, hereditary coproporphyria, porphyria cutanea tarda, and variegate porphyria. The most common type of porphyria is porphyria cutanea tarda. Some of the symptoms of porphyria include blistering, swelling, and itching when the skin is exposed to sun. Other symptoms may also include pain, numbness or tingling, vomiting, constipation, and intellectual disability. There is no known cure for porphyria, but the various types have different courses of treatment, and may include bone marrow transplant.[1]

Most porphyrias are inherited conditions with either an autosomal dominant or autosomal recessive pattern of inheritance. However, some forms of porphyria can be caused by environmental factors such as infections or exposures to certain prescription drugs. Porphyrias caused by environmental factors are called sporadic or acquired porphyria.[2][3]
Last updated: 3/22/2017

How is porphyria diagnosed?

Many of the signs and symptoms of porphyria are similar to those of other more common diseases. Also, because porphyria is rare, many doctors have not seen cases of the disorder before, making it more difficult to diagnosis. Because porphyria's signs and symptoms usually aren't distinctive, laboratory tests are required to make a definitive diagnosis and to determine which type of porphyria is involved.[4]

If your doctor suspects porphyria, he or she may recommend the following tests:[4][5]

  • Urine test. If you have a form of acute porphyria, a urine test may reveal elevated levels of two substances: porphobilinogen and delta-aminolevulinic acids, as well as other porphyrins.
  • Blood test. If you have a form of cutaneous porphyria, a blood test may show an elevation in the level of porphyrins in the liquid part of your blood (plasma).
  • Stool sample test. Analysis of a stool sample may reveal elevated levels of some porphyrins that may not be detected in urine samples. This test may help your doctor determine your specific type of porphyria.
Genetic testing may also be used to confirm the diagnosis.[5]
Last updated: 11/4/2016

Is genetic testing clinically available for porphyria?

Yes. Genetic Testing Registry (GTR) lists laboratories offering clinical genetic testing for several types of porphyria. Clinical genetic tests are ordered to help diagnose a person or family and to aid in decisions regarding medical care or reproductive issues. Talk to your health care provider or a genetic professional to learn more about your testing options.
Last updated: 11/4/2016

How can I find a genetics professional in my area?

To find a medical professional who specializes in genetics, you can ask your doctor for a referral or you can search for one yourself. Online directories are provided by GeneTests, the American College of Medical Genetics, and the National Society of Genetic Counselors. If you need additional help, contact a GARD Information Specialist. You can also learn more about genetic consultations from Genetics Home Reference.
Last updated: 8/23/2016

We hope this information is helpful. We strongly recommend you discuss this information with your doctor. If you still have questions, please contact us.

Warm regards,
GARD Information Specialist

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  1. Porphyria. National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK). February 26, 2014; http://www.niddk.nih.gov/health-information/health-topics/digestive-diseases/porphyria/Pages/facts.aspx. Accessed 5/26/2015.
  2. Porphyria. MedlinePlus. September 24, 2014; http://www.nlm.nih.gov/medlineplus/porphyria.html. Accessed 5/26/2015.
  3. Porphyria. Genetics Home Reference. July 2009; http://ghr.nlm.nih.gov/condition=porphyria. Accessed 5/26/2015.
  4. Porphyria. MayoClinic.com. May 20, 2014; http://www.mayoclinic.com/health/porphyria/DS00955/METHOD=print. Accessed 11/4/2016.
  5. Tests for Porphyria diagnosis. American Porphyria Foundation. http://www.porphyriafoundation.com/testing-and-treatment/testing-for-porphyria/tests-for-porphyria-diagnosis. Accessed 11/4/2016.