Porphyria overview

Porphyrias are predominantly inherited disorders caused by a dysfunction of one of the enzymes in the porphyrin-heme biosynthetic pathway,¹ which the body uses to produce heme for hemoglobin in the blood.

The different types of porphyria can be classified in a variety of ways, including acute or nonacute.^1,2 Acute porphyrias, which cause acute neurological attacks, include acute intermittent porphyria, variegate porphyria, hereditary coproporphyria and δ-aminolevulinic acid dehydratase, or ALA-D, deficiency porphyria.¹ The term “acute porphyrias” does not fully describe the clinical features, which can be prolonged and chronic.² Nonacute porphyrias include porphyria cutanea tarda, erythropoietic protoporphyria, congenital erythropoietic porphyria and hepatoerythropoietic porphyria.¹

Symptoms

Patients with porphyria present in three different ways: with cutaneous lesions, acute attacks, or both.³ The clinical features of an acute attack associated with the acute porphyrias vary greatly. The most common symptom is severe abdominal pain, which may be accompanied by neurological and psychiatric symptoms.³

Statistics

According to the American Porphyria Foundation, all forms of porphyria combined affect fewer than 200,000 Americans.⁴ Porphyria cutanea tarda, acute intermittent porphyria and erythropoietic protoporphyria are the three most common porphyrias.⁵

Seeking diagnosis and care

Porphyrias, especially the acute porphyrias, can be a challenge to diagnose because symptoms can vary from patient to patient and the clinical signs and symptoms may mimic other more common conditions.² The majority of the carriers of the gene mutation for the acute porphyrias may never have an attack, and others may only have one or a few acute attacks throughout life.² In addition, physicians may not be as familiar with the disorders because of their rarity.⁶

In general, a diagnosis between types of porphyrias can only be definitively made after analysis of clinical symptoms and family history, biochemical measurement of porphyrins and porphyrin precursors, determination of specific enzymatic activities and mutation analyses.¹

Once a specific type of porphyria has been diagnosed, healthcare professionals can work to determine appropriate management as each porphyria requires a different approach.⁵

 Sources
1. Gutierrez, Pamela et al. Diagnosis and Treatment of the Acute Porphyrias: An Interdisciplinary Challenge. Skin Pharmacol Appl Skin Physiol. 2001;14:393–400.
2. Anderson, Karl E. Recommendations for the Diagnosis and Treatment of Acute Porphyrias. 2005; 142;439-451.
3. Thadani, Helen et al. Diagnosis and management of porphyria. British Medical Journal. 2000;320;1647-1651.
4. American Porphyria Foundation (APF). About Porphyria.  http://www.porphyriafoundation.com/about-porphyria. Last accessed 10/13/11.
5. Anderson, Karl E. Approaches to Prevention and Treatment of Human Porphyrias. The Porphyrin Handbook. 2003;14;248-284.
6. Dombeck, Teague et al. The Porphyrias. Emerg Med Clin N Am. 2005;23;885–899.