Porphyria (por-FEER-ee-a) refers to a group of acquired or inherited disorders that result when problems occur in the pathway the body uses to convert chemicals called porphyrins into heme, a compound primarily found in red blood cells. Common symptoms of porphyria are sensitivity to light, skin rashes, abdominal (ab-DAH-mih-nul) pain, discoloration of the urine, and changes in mental status or personality.
When individuals inherit a defective gene * from one or both parents, they may develop a form of porphyria. Sometimes, however, individuals who do not inherit the disorder may still develop it. The term porphyria derives from the Greek word porphura, which means purple pigment. In many patients experiencing an acute attack of this disorder, body fluids, such as the urine, turn purple in color.
Porphyria is divided into eight different types. All eight types are a result of a problem in the chemical process by which the body produces heme, a compound that carries oxygen and makes blood red. The production of heme requires eight different enzymes * . If any one of these enzymes fails, compounds that should be turned into heme build up in the body instead, especially in the liver * and in the bone marrow * , and cause problems. Some of these compounds are called porphyrins (PORfi-rinz), from which the disease takes its name. It is the failure of various enzymes that causes the different forms of porphyria.
Some of the eight types of porphyria are rare. While exact numbers are not available, an estimated 1 person in 10,000 to 50,000 may be affected with some form of porphyria.
This form of porphyria only occurs when it is triggered by certain drugs, starvation or crash dieting, infection, and some hormones * in women. This form of porphyria is more common in women than in men. It usually occurs first during the early adult years. Symptoms include stomach pain, leg cramps, and muscle weakness. As its name indicates, it tends to occur intermittently (periodically). In its most acute * forms, it can cause seizures * , paralysis * , depression * , and even hallucinations * or coma * .
Porphyria cutanea tarda (ku-TAY-ne-a TAR-da) (PCT) is the most common form of porphyria and causes blisters on the parts of the body that are exposed to sunlight. Some people with this form also develop liver disease, and up to 50 percent of patients with PCT also have hepatitis * C. Substances that can cause an attack of PCT include alcohol, heavy intake of iron (iron overload), or the use of birth control pills. Porphyria cutanea tarda usually does not affect younger women. However, the increased use of substances that can trigger an attack, such as alcohol or birth control pills, has resulted in increased numbers of younger women developing the disease. This type of porphyria is not inherited. Only about 20 percent of cases have a family history of the disease.
Protoporphyria (pro-to-por-FEER-ee-a) usually starts in childhood. The skin is extremely sensitive to sunlight, and painful rashes, redness, and itching may develop.
Medical professionals diagnose porphyria when they find an excess of porphyrins (compounds involved in making heme) in the urine. More laboratory tests help pinpoint specific forms of porphyria. Individuals who have received a diagnosis of porphyria should consult their doctor about all medicines, other drugs, or hormones they are taking or thinking about taking, as some are dangerous to individuals with this disorder.
Treatments vary depending on the patient's specific needs:
See also Eating Disorders: Overview • Genetic Diseases: Overview • Hemochromatosis • Hepatitis
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MedlinePlus. “Porphyria.” U.S. National Library of Medicine, National Institutes of Health. https://www.nlm.nih.gov/medlineplus/porphyria.html (accessed August 12, 2015).
National Human Genome Research Institute. “Learning about Porphyria.” National Institutes of Health. https://www.genome.gov/19016728 (accessed August 12, 2015).
National Institute of Diabetes and Digestive and Kidney Diseases. “Porphyria.” National Institutes of Health. (accessed August 12, 2015).
American Porphyria Foundation. 4900 Woodway, Suite 780, Houston, TX 77056. Toll-free: 866-273-3635. Website: http://www.porphyriafoundation.com (accessed August 12, 2015).
National Institutes of Health Office of Rare Diseases Research Genetic and Rare Diseases Information Center. PO Box 8126, Gaithersburg, MD 20898. Toll-free: 888-205-2311. Website: https://rarediseases.info.nih.gov/GARD (accessed November 12, 2015).
National Organization for Rare Disorders. 55 Kenosia Ave., Danbury, CT 06810. Toll-free: 800-999-6673. Website: http://www.rarediseases.org (accessed November 12, 2015).
* genes (JEENS) are chemical structures composed of deoxyribonucleic acid (DNA) that help determine a person's body structure and physical characteristics. Inherited from a person's parents, genes are contained in the chromosomes found in the body's cells.
* enzymes (EN-zimes) are proteins that help speed up a chemical reaction in a cell or organism.
* liver is a large organ located beneath the ribs on the right side of the body. The liver performs numerous digestive and chemical functions essential for health.
* bone marrow is the soft tissue inside bones where blood cells are made.
* hormones are chemical substances that are produced by various glands and sent into the bloodstream carrying messages that have certain effects on other parts of the body.
* acute describes an infection or other illness that comes on suddenly and usually does not last very long.
* seizures (SEE-zhurs), also called convulsions, are sudden bursts of disorganized electrical activity that interrupt the normal functioning of the brain, often leading to uncontrolled movements in the body and sometimes a temporary change in consciousness.
* paralysis (pah-RAHL-uh-sis) is the loss or impairment of the ability to move some part of the body.
* depression (de-PRESH-un) is a mental state characterized by feelings of sadness, despair, and discouragement.
* hallucinations (ha-LOO-sin-AYshuns) occur when a person sees or hears things that are not really there. Hallucinations can result from nervous system abnormalities, mental disorders, or the use of certain drugs.
* coma (KO-ma) is an unconscious state, like a very deep sleep. A person in a coma cannot be awakened, and cannot move, see, speak, or hear.
* hepatitis (heh-puh-TIE-tis) is an inflammation of the liver. Hepatitis can be caused by viruses, bacteria, and a number of other noninfectious medical conditions.