This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Metabolism of nucleic acids, Subject name: Biochemistry
Orotic aciduria is due to deficiency of 
Select and explain. 
A. Decarboxylase, B. Tyrosinase, C. Isomerase, D. Homogentisate oxidase
A: Decarboxylase
Answer: A: Decarboxylase 
Explanation: Orotic aciduria an autosomal recessive disorder, can be caused by a deficiency in the enzyme UMPS, a bifunctional protein that includes the enzyme activities of orotate phosphoribosyltransferase and orotidine 5'-phosphate decarboxylase.