These patients have a homozygous deficiency of ALA dehydrase activity which produces acute attacks of porphyria. The absence of PBG distinguishes ALA deficiency from acute intermittent porphyria, variegate porphyria, and coproporphyria which also can have increased ALA in the urine but is seen with increase PBG and in the latter disorder coproporphyrin as well.
Management is similar to that of acute intermittent porphyria .