Use

This test is used to confirm the diagnosis of aminolevulinic acid dehydratase (ALAD) deficiency porphyria using washed erythrocyte specimens. ALAD deficiency porphyria is an autosomal recessive acute hepatic porphyria characterized by neurologic symptoms similar to those seen in acute intermittent porphyria. A marked deficiency of ALAD results in the accumulation and excretion of large amounts of aminolevulinic acid (ALA) with essentially normal urinary porphobilinogen levels, differentiating it from other forms of acute porphyria. ALAD activity can also be inhibited by other factors like lead intoxication, but this test is not useful for detecting lead intoxication.