An infant with hyperglycemia, ketosis, and refractory high–anion gap metabolic acidosis: a diagnostic puzzle
Surbhi Gyani, Sahil Dabas, Arpita Chattopadhyay, Sunita Bijarnia-MahayAbstract
Introduction
Atypical presentations of inborn errors of metabolism, such as methylmalonic acidemia, often mimic metabolic emergencies such as diabetic ketoacidosis (DKA) or acute encephalitis syndrome. Here we present the case of an 8-month-old girl who was admitted with severe dehydration, respiratory distress, and rapidly progressing encephalopathy.
Methods
The patient was initially treated for infantile-onset DKA. However, several features were atypical for DKA, such as persistent metabolic acidosis despite correction of hyperglycemia, hyperammonemia, and rising lactate concentrations.
Results
Urine organic acid analysis by gas chromatography–mass spectrometry raised suspicion of an underlying inborn error of metabolism, whereas genetic testing identified a homozygous MMAA pathogenic variant consistent with cobalamin A (cblA)–type methylmalonic acidemia.
Discussion
Despite substantial overlap in clinical presentation, the child received timely intervention and recovered completely.