Lead poisoning in inherited delta-aminolevulinic acid dehydratase deficiency.
delta-Aminolevulinic acid dehydratase (ALA-D), respectively porphobilinogen synthase, EC 4.2.1.24) activity can be lowered by toxic, metabolic and hereditary factors. A 30-year-old painter was suffering from lead poisoning with an acute abdominal-neurologic syndrome and anemia. Blood lead was measured at 414 micrograms/l. Urinary ALA and coproporphyrin excretion as well as erythrocyte protoporphyrin had increased extremely, whereas ALA-D activity in erythrocytes had decreased extremely to 8% of controls. Excretion parameters, protoporphyrin, hemoglobin and lead returned to normal after treatment, but four years later ALA-D activity still remained diminished (30% of controls). An inherited enzyme deficiency was assumed and found in the mother, analogous to the subnormal ALA-D activity in heterozygotes of four other families. The inherited enzyme deficiency sensitized the patient to lead exposure and intoxication, which is a toxogenetic disease in this case.
D000328:Adult; D004492:Edetic Acid / Q000627:therapeutic use; D004912:Erythrocytes / Q000032:analysis; D006801:Humans; D007854:Lead / Q000097:blood; D007855:Lead Poisoning / Q000188:drug therapy / Q000201:enzymology* / Q000209:etiology; D008297:Male; D000623:Porphobilinogen Synthase / Q000172:deficiency*; D011524:Protoporphyrins / Q000097:blood
D011524:Protoporphyrins; D007854:Lead; D004492:Edetic Acid; D000623:Porphobilinogen Synthase