Hereditary coproporphyria

Hereditary Coproporphyria

Structure of Coproporphyrinogen III

Hereditary coproporphyria (HCP) is a type of porphyria, which is a group of rare metabolic disorders resulting from a deficiency in one of the enzymes involved in the heme biosynthesis pathway. HCP is characterized by a deficiency of the enzyme coproporphyrinogen oxidase, leading to the accumulation of porphyrins and their precursors, which can cause a variety of symptoms.

Pathophysiology

Hereditary coproporphyria is caused by mutations in the CPOX gene, which encodes the enzyme coproporphyrinogen oxidase. This enzyme is responsible for the conversion of coproporphyrinogen III to protoporphyrinogen IX in the heme biosynthesis pathway. A deficiency in this enzyme leads to the accumulation of coproporphyrinogen III and other porphyrin precursors, which can cause neurovisceral attacks and cutaneous symptoms.

Clinical Presentation

The clinical manifestations of hereditary coproporphyria can vary widely among individuals. Common symptoms include:

• Abdominal pain
• Neurological disturbances such as seizures, neuropathy, and psychiatric symptoms
• Photosensitivity leading to skin lesions

The symptoms are often triggered by factors such as certain medications, alcohol, fasting, and hormonal changes.

Diagnosis

Diagnosis of hereditary coproporphyria is based on clinical symptoms, biochemical tests, and genetic testing. Biochemical tests typically show elevated levels of coproporphyrin in the urine and feces. Genetic testing can confirm mutations in the CPOX gene.

Management

Management of hereditary coproporphyria involves avoiding triggers, managing symptoms, and in some cases, administering heme preparations to reduce the production of porphyrin precursors. Patients are advised to avoid drugs and other factors that can precipitate attacks.

Prognosis

The prognosis for individuals with hereditary coproporphyria varies. With proper management and avoidance of triggers, many individuals can lead relatively normal lives. However, severe attacks can be life-threatening and require prompt medical attention.

Related Pages

• Porphyria
• Heme
• CPOX gene
• Photosensitivity