Clinical and Laboratory Findings in OTC Deficiency

We have collected most of the reported cases of OTC deficiency between 1962, when the first case was reported, through 2002. We searched Index Medicus(Pub Med)and Reference Update(ISI) for the keywords ornithine transcarbam(yl)(oyl)ase, ornithine carbam( yl)(oyl) transferase, and other keywords for elements of the urea or ornithine cycle in articles written in English, German, Spanish and French. Articles written in Japanese were not included. Copies of each article were reviewed and tables were constructed listing in order of year of publication all female cases (Table 7–1), neonatal male cases (onset 0-28 days after birth)(Table 7–2) and late-onset male cases (Table 7–3)(>28 days). We included clinical findings reported at onset of the illness and up to the time of diagnosis. Symptoms we included were (a) vomiting; (b) decreased level of consciousness from lethargy to coma; (c) focal or generalized seizure activity; (d) abnormal behavior which persisted or recurred; (e) avoidance of protein-containing foods or intolerance of infant formulas; (f) delayed growth > 3% of predicted height or weight); (g) delayed development (IQ or other cognitive tests below normal); (h) incoordination (usually ataxia); and (j) some form of persistent central nervous system (CNS) deficit. We also included in the list of clinical findings (i) a positive family history of OTC-type illness, defined as proof of OTC deficiency in the mother, siblings or first-order relatives, or a history of at least two neonatal male deaths in siblings without a known cause.