Erythropoietic Protoporphyria (EPP)

Erythropoietic protoporphyria (EPP) is caused by a deficiency of the enzyme ferochelatase. EPP can be inherited from one parent, autosomal dominantly or from both parents, autosomal recessively.



protoporphyrin accumulates in the erythrocytes, plasma, skin and liver.

In erythropoiesis, the pathway is controlled by iron.


Elevated iron raises the ALAS2 enzyme which increases the accumulation of porphyrins in the bone marrow, aggravating the symptoms of erythropoietic porphyria; decreased iron lowers the ALAS2 enzyme which lowers the accumulation of porphyrins in the bone marrow, improving the symptoms go erythropoietic porphyria (check this).


There are genes outside of the heme synthesis pathway that can aggravate erythropoietic porphyria. Hereditary hemochromatosis can aggravate erythropoietic porphyria by increasing the iron levels in the body



"During low iron availability, IRE-binding proteins (mainly homolog 2: IRP2) bind to this IRE, block translation, and diminish ALAS2 activity."



Porphyrins absorb ultraviolet light (

Porphyrins are deposited in the epidermis of the skin (


"Light energy absorption by porphyrins results in the generation of oxygen reactive species, overcoming the protective cellular mechanisms and leading to molecular, cell, and tissue damage (









Congenital erythropoietic porphyria (CEP)erythropoietic protoporphyria (EPP), x-linked porphyria (XLP)