Acute intermittent porphyria (AIP) is a rare genetic metabolic disorder characterized by a deficiency in the enzyme porphobilinogen deaminase (PBGD), which is involved in the synthesis of heme, an essential component of hemoglobin. This enzyme deficiency leads to the accumulation of certain chemicals called porphyrins and their precursors, known as porphyrinogens, in the body.
The condition is inherited in an autosomal dominant manner, meaning that an affected individual typically inherits the faulty gene from one of their parents. However, not all individuals with the gene mutation will develop symptoms, as the condition is often triggered by certain factors such as hormonal changes, drugs, alcohol, stress, and fasting.
The hallmark features of acute intermittent porphyria include episodes of severe abdominal pain, often accompanied by nausea, vomiting, constipation, and occasionally diarrhea. These attacks can last for days to weeks and may be associated with autonomic nervous system dysfunction, peripheral neuropathy, muscle weakness, and in severe cases, psychiatric symptoms.
Diagnosis of AIP involves a combination of clinical presentation, biochemical testing to detect elevated levels of porphyrins and related chemicals in urine and blood, and genetic testing to confirm the presence of a mutation in the gene responsible for PBGD deficiency.
Treatment of acute intermittent porphyria usually involves managing the symptoms during an attack, with strategies including intravenous glucose, medications to relieve pain and nausea, and avoidance of triggers. In some cases, regular administration of a medication called hemin can help prevent recurrent attacks. Genetic counseling is recommended for affected individuals and their families to understand the inheritance pattern and the risk of passing on the condition to future generations.
