Pathogenesis of acute porphyria

The pathogenesis of the clinical manifestations of acute porphyria has been considered in the light of their pathological changes and their aberrations of the haem biosynthetic pathway. These manifestations may be explained almost entirely upon a neurogenic basis. A number of hypotheses have been considered to explain the clinical, pathological and biochemical features. Of these hypotheses two seem more impressive: (i) the neurological manifestations may be explained by a deficiency of haem in neural tissues; (ii) the porphyrin precursor 5-aminolaevulinic acid (ALA) may have in addition specific pharmacological activity.