orotic aciduria pathway 2015-02-12T10:34:32Z Alterations in the pyrimidine biosynthetic pathway resulting in excessive excretion of orotic acid. The inborn metabolic condition is primarily due to deficiency in the bifunctional uridine monophosphate (UMP) synthetase enzyme. Orotic aciduria is also due to ornithine transcarbamylase (OTC) deficiency and its hyperammonemia. PW:0001604 orotic aciduria disease pathway pathway vpetri inborn error of purine-pyrimidine metabolism pathway