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What is A 4 year old girl presented to hospital with failure to thrive. Her peripheral blood smear showed megaloblastic anemia. Vitamin B12 & folate were given but anemia did not improve. Enzyme assay from the cultured PBMC showed deficiency of OP (Orotate Phospho Ribosyl Transferase). What could be the probable diagnosis ? and explain in detail?
Orotic aciduria Due to deficiency of orotate phosphoribosyl transferase and OMP decarboxylase Leads to defect in DNA Synthesis Characterizedby : Excretion of orotic acid in urine, Severe anemia Megaloblastic Not improved with folate /vitamin B12/vitamin C Retarded growth Rx- Feeding diet rich in uridine / cytidine