Inherited and/or acquired disorders of in which there are enzyme deficiencies involved in heme biosynthesis, resulting in build up of<unk> s (Porphobilinogen and δ-Aminolevulinic acid [ALA])
Heme is a component of many essential hemoproteins, such as hemoglobin, myoglobin and cytochromes, including the cytochrome P450 enzymes
Acute intermittent<unk>  is most salient to EM
The first enzyme in the heme production pathway is ALA synthase (ALAS), which controls the rate of heme synthesis in the liver. This enzyme is down-regulated by heme.
The enzyme deficiencies in<unk>  limit the capacity of the liver to increase heme synthesis.
When drugs, hormones or other factors that induce ALAS and CYPs are given, ALA and porphobilinogen (PBG) are overproduced and accumulate, and a neurovisceral attack may develop
Infection, metabolic stress
Carbohydrate deficiency
Tobacco, ETOH<unk> ogenic drugs: sulfonamides, barbiturates, rifampin or metoclopramide
Porphyria
Abdominal aortic aneurysm
Scurvy
Aortocaval fistula
Rickets
Acute gastroenteritis
Pruritus ani
Aortoenteric fisulta