What is the difference between paraerythropoietic porphyria and erythropoietic porphyria?

Paraerythropoietic porphyria (PEP) and erythropoietic porphyria (EP) are both rare, inherited disorders that affect the production of heme, a molecule that is essential for the proper functioning of red blood cells.

Key differences between PEP and EP include:

Genetics: PEP is caused by mutations in the ALAS2 gene, which encodes the enzyme aminolevulinic acid synthase 2. EP, on the other hand, is caused by mutations in different genes, depending on the specific type of EP. The most common type of EP, erythropoietic protoporphyria (EPP), is caused by mutations in the FECH gene, which encodes the enzyme ferrochelatase. Both PEP and EP are inherited in an autosomal dominant manner, meaning that only one copy of the mutated gene is needed to cause the disorder.

Clinical manifestations: The clinical manifestations of PEP and EP can vary, but both disorders can cause photosensitivity, skin fragility, and blisters. PEP can also cause abdominal pain, vomiting, and neurological problems, such as seizures and mental retardation. EPP, on the other hand, is characterized by recurrent episodes of intense pain and swelling in the skin, as well as blisters and skin fragility.

Treatment: There is no cure for PEP or EP, but treatment can help manage the symptoms of the disorders. Treatment options for PEP may include blood transfusions, intravenous heme infusions, and medications to reduce the production of porphyrins. Treatment options for EPP may include avoiding sun exposure, using sunscreen, and medications to reduce the production of protoporphyrin.

Prognosis: The prognosis for PEP and EP can vary depending on the severity of the disorders. While some individuals with PEP or EP may have mild symptoms that do not significantly affect their daily lives, others may experience severe symptoms that can lead to significant disability or even death.