Acute intermittent porphyria - impact of mutations found in the hydroxymethylbilane synthase gene on biochemical and enzymatic protein properties

Abstract

Acute intermittent porphyria is an autosomal dominantly inherited disorder, classified as acute hepatic porphyria, caused by a deficiency of hydroxymethylbilane synthase (EC 2.5.1.61, EC 4.3.1.8, also known as porphobilinogen deaminase, uroporphyrinogen I synthase), the third enzyme in heme biosynthesis. Clinical features include autonomous, central, motor or sensory symptoms, but the most common clinical presentation is abdominal pain caused by neurovisceral crises.

A diagnosis of acute intermittent porphyria is crucial to prevent life-threatening acute attacks. Detection of DNA variations by molecular techniques allows a diagnosis of acute intermittent porphyria in situations where the measurement of porphyrins and precursors in urine and faeces and erythrocyte hydroxymethylbilane synthase activity is inconclusive.