Objective: To alert the physicians to the possibility of a late-onset inbor
n error of metabolism in an apparently previously healthy patient with acut
e clinical presentation,
Design: Case report.
Setting: Pediatric unit and general intensive care unit
Patient An apparently previously healthy 12-yr-old female presented acutely
with vomiting, fever, bronchopneumonia, and progressive loss of consciousn
ess associated with ketoacidosis, hyperglycemia, and hyperammonemia. She di
ed 3 days later with a diagnosis of insulin-dependent diabetes mellitus,
Interventions: Intravenous hydration, glucose and insulin, mechanical venti
lation.
Measurements and Main Results: Organic acid analysis on a postmortem sample
of aqueaus humor revealed high levels of methylmalonic acid. Enzymatic stu
dies on cultured fibroblasts were consistent with the diagnosis of cb/B met
hylmalonic aciduria.
Conclusions: The diagnosis of cb/B methylmalonic aciduria was made in a pos
tmortem patient who died with a misdiagnosis of insulin-dependent diabetes
mellitus. Unclear biochemical findings and positive family history should s
trongly lead to suspicion of an inborn error of metabolism in an apparently
previously healthy critically ill patient.