orotic aciduria

(redirected from orotic aciduria without megaloblastic anaemia)

o·rot·ic ac·i·du·ri·a

(ōr-ot'ik as'i-dyu'rē-ă), [MIM*258900]
A rare disorder of pyrimidine metabolism characterized by hypochromic anemia with megaloblastic changes in bone marrow, leukopenia, retarded growth, and urinary excretion of orotic acid; autosomal recessive inheritance, caused by mutation in the uridine monophosphatate synthase gene (MMPS) on 3q13.
[orotic acid + G. ouron, urine]

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. 

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.