Acute intermittent porphyria (AIP) is a rare metabolic disorder that is the most common of the acute porphyries and is characterized by enzymatic defect of porphobilinogen
deaminase with depot and increased excretion of porphyrins and their precursors (1).
Allosteric inhibition of human lymphoblast and purified porphobilinogen
deaminase by protoporphyrinogen and coproporphyrinogen.
Chlorophyll biosynthesis in higher plants was carried and accomplished by sequential reactions, D-aminolevulinic acid (ALA), porphobilinogen
(PBG), uroporphyrinogen III (Urogen III), coproporphyrinogen III (Coprogen III), protoporphyrin IX (Proto IX), Mg-protoporphyrin IX (Mg- Proto IX) and protochlorophyllide (Pchlide) were the major synthetic precursors during these sequential reactions (Ilag et al.
4] During an acute attack, haem precursors accumulate in front of the deficient enzyme, which in AIP is porphobilinogen
deaminase and in VP protoporphyrinogen oxidase.
1 Acute intermittent porphyria (AIP), an autosomal dominant disorder, is a common type of neurologic porphyria in which mutation of the porphobilinogen
deaminase (PBGD) gene plays an important role.
Mutation hotspots in the human porphobilinogen
deaminase gene: Recurrent mutations G111R and R173Q occurring at CpG motifs.
Modified Ehrlich's reagent was used to react with the porphobilinogen
(PBG) final product to yield a pink-colored compound, which was measured at 555nm.
For confirmatory diagnosis, porphobilinogen
deaminase (PBGD) test was done which was found to be positive.
The Hoesch test: bedside screening for urinary porphobilinogen
in patients with suspected porphyria.
Thus, N deficiency leads to decreased synthesis of glutamate, reduced ALA porphobilinogen
synthesis and, consequently, a decrease in the biosynthesis of chlorophyll, which leads to the development of chlorosis in plants (CHU et al.
3-5) Test for urinary porphobilinogen
was done by the method of Schwartz et al4 and was negative.
Urine examination was normal including porphobilinogen