天主教高雄教區 群組

Orotic aciduria is a rare inherited metabolic disorder characterized by the excessive excretion of orotic acid in the urine due to a defect in pyrimidine (DNA and RNA building block) synthesis. It is most commonly caused by deficiency of the enzyme uridine monophosphate synthase (UMPS).

Cause

Classic hereditary orotic aciduria results from mutations in the UMPS gene, leading to deficiency of the UMPS enzyme, which has two catalytic activities:

• Orotate phosphoribosyltransferase (OPRT)

• Orotidine-5′-phosphate decarboxylase (OMP decarboxylase)