Question

An 18-month-old boy was referred to the pediatrics clinic because of persistent anemia and associated failure to thrive. Laboratory analysis confirmed a microcytic anemia and revealed blood lead levels of 50 mg/dL (2 times normal levels) and high levels of coproporphyrinogen III in the urine. The child was put on chelation therapy and recovered uneventfully. The cause of the child's difficulty was most likely due to the effects of the lead. The findings in this patient most closely reflect lead inhibition of which of the following enzymes of heme biosynthesis?a) δ-aminolevulinic acid (ALA) dehydrataseb) ferrochelatasec) porphobilinogen (PBG) deaminased) proporphyrinogen III cosynthasee) uroporphyrinogen decarboxylase

Answer 1

B) Ferrochelatase

Step-by-step explanation:

The hematological effects of lead poisoning includes the inhibition of the body's ability to produce hemoglobin. This is done by interfering with several enzymatic steps in the heme synthesis pathway.

Lead inhibits or decreases heme synthesis by inhibiting Ferrochelatase enzyme activity.

Ferrochelatase catalyses the insertion of iron into protoporphyrin IX and is very sensitive to lead.