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UROD gene

Reviewed by Medicinsk Expert•Last updated: 2026-10-22•Gene

UROD gene

The UROD gene provides instructions for making an enzyme required for the production of heme, a vital component of hemoglobin and other proteins.

Normal Function

The UROD gene provides instructions for making an enzyme known as uroporphyrinogen decarboxylase. This enzyme is involved in the production of a molecule called heme. Heme is vital for all of the body's organs and is an essential component of iron-containing proteins called hemoproteins, including hemoglobin, which carries oxygen in the blood.

The production of heme is a multi-step process requiring eight different enzymes. Uroporphyrinogen decarboxylase is responsible for the fifth step, in which carbon and oxygen atoms are removed from uroporphyrinogen III to form coproporphyrinogen III.

Health Conditions Related to Genetic Changes

Porphyria

Mutations in the UROD gene are responsible for two forms of porphyria: porphyria cutanea tarda and hepatoerythropoietic porphyria.

  • Porphyria cutanea tarda: This is the most common type of porphyria. Mutations in one copy of the UROD gene in each cell reduce enzyme activity by approximately 50 percent. This buildup of porphyrins, combined with factors like alcohol use, smoking, hormones, excess iron, or hepatitis C/HIV infections, leads to the condition.
  • Hepatoerythropoietic porphyria: Mutations in both copies of the UROD gene in each cell reduce enzyme activity to less than 10 percent of normal. This leads to a severe accumulation of porphyrins in the body, causing the characteristic features of this type of porphyria.

Other Names for This Gene

  • DCUP_HUMAN
  • UD - Uroporphyrinogen decarboxylase
  • UPD
  • URO-D
  • Uroporphyrinogen III decarboxylase
  • Uroporphyrinogen-III carboxy-lyase

Frequently Asked Questions

PCT primarily affects the skin, causing blistering lesions, increased skin fragility, and hyperpigmentation (darkening) in sun-exposed areas. Triggers include alcohol consumption, smoking, excess iron, certain hormones (like estrogen), and infections such as hepatitis C or HIV. Avoiding these triggers is crucial for management.
Porphyria cutanea tarda (PCT) usually requires a mutation in one UROD gene copy and additional triggers, so it's not strictly inherited in a simple Mendelian pattern for all cases. However, the genetic predisposition can be passed on. Hepatoerythropoietic porphyria (HEP) is an autosomal recessive condition, meaning a child must inherit two mutated UROD copies (one from each parent) to develop the severe form. If you have a UROD mutation, genetic counseling can help assess the specific risk for your family.
Diagnosis typically involves blood and urine tests to measure levels of porphyrins, which are chemicals that build up in the body. Elevated levels of specific porphyrins, particularly uroporphyrin, indicate PCT. Genetic testing for UROD mutations can confirm the diagnosis and distinguish it from other porphyrias.
Source: MedlinePlus, National Library of Medicine

MedlinePlus brings together authoritative health information from the National Library of Medicine (NLM), the National Institutes of Health (NIH), and other government agencies and health-related organizations.