ABSTRACT
ALAD porphyria is an autosomal recessive disorder resulting from a homozygous aminolevulinic
acid dehydratase (ALAD) deficiency. Because of an almost complete lack of ALAD activity,
patients excrete a large amount of ALA, but not PBG, into urine. The symptoms in this
disease are similar to those seen in AIP, but ALAD porphyria can be differentiated
from AIP by its autosomal recessive, rather than dominant, inheritance, by the lack
of PBG overproduction, and by markedly decreased ALAD activity.
KEY WORDS
ALAD - ALA dehydratase - δ-aminolevulinate dehydratase - ALAD porphyria - porphyria
