intermittent acute porphyria n.
Abbr. IAP
Porphyria caused by overproduction of delta-aminolevulinic acid, with greatly increased urinary excretion of it and of porphobilinogen, due to a deficiency of porphobilinogen deaminase. It is characterized by intermittent acute attacks of hypertension, abdominal colic, psychosis, and neuropathy. Also called acute intermittent porphyria.