sentences:  Orotic aciduria was first reported in 1959 when excess orotic acid was found in the urine of an infant.When individuals have a mutation leading to loss of orotate phosphoribosyltransferase activity and thus UTP production, orotic acid builds up and can be as high as 1.5g/day in infant urine.This is because UTP is the normal end product in healthy individuals in the pyrimidine synthetic pathway and normally regulates the pathway.