oroticaciduria

oroticaciduria

 [o-rot″ik-as″ĭ-du´re-ah]
a hereditary defect of pyrimidine metabolism associated with excessive urinary excretion of orotic acid, and characterized by megaloblastic anemia, crystalluria, and frequently physical and mental retardation.

orotic aciduria

A rare autosomal recessive disorder (OMIM:258900) of pyrimidine metabolism characterised by megaloblastic anaemia and orotic acid crystalluria, often associated with physical and mental retardation and, in some cases, congenital malformations and immune defects. 

Lab
Hypochromic anaemia with megaloblastic changes in bone marrow, decreased WBCs, increased orotic acid in urine.
 
Molecular pathology
Caused by defects of UMPS, which encodes uridine monophosphate synthetase, a bifunctional enzyme that catalyses the last two steps of pyrimidine synthesis.