Orotic aciduria is due to deficiency of-

Oroticaciduria is a rare, Autosomal recessive disorder. It is the most common metabolic error in Pyrimidine Synthesis. OP (Orotate Phospho Ribosyl Transferase) & Decarboxylase are bifunctional enzymes in pyrimidine synthesis. There are two types of Orotic acidurias: Type I : Both enzymes deficient i.e. OP(Orotate Phosphoribosyl Transferase) and OMP Decarboxylase(it is a bifunctional enzyme) Type II - Only one enzyme deficient (mostly OMP decarboxylase)