Which of the following anemias is characterized by a defect in the enzyme dihydroorotate dehydrogenase, leading to impaired pyrimidine synthesis?

A Hereditary sideroblastic anemia
B Hereditary xanthinuria
C Pyrimidine 5'-nucleotidase deficiency
D Orotic aciduria ✓

Explanation

Orotic aciduria is a rare genetic disorder characterized by a defect in the enzyme dihydroorotate dehydrogenase, leading to impaired pyrimidine synthesis and resulting in megaloblastic anemia.

Source

Molecular Biology and Genetics of Anemia
Hematology Hematology: Anemia Hematology: Anemia Hard MEDICAL Confidence: medium