Beta-ketothiolase deficiency mimicking diabetic ketoacidosis in an infant: A diagnostic dilemma: A case report

Abstract

Beta-ketothiolase (BKT) deficiency is a rare disorder of isoleucine and ketone body metabolism caused by ACAT1 mutations. We report a 6-month-old infant presenting with fever, shock, hyperglycemia, ketosis, and severe metabolic acidosis (pH 6.9) mimicking diabetic ketoacidosis. However, the young age of presentation, normal glycated hemoglobin, hyperammonemia, and refractory high anion gap metabolic acidosis raised suspicion of an inborn error of metabolism. Infant improved after supportive care, including peritoneal dialysis. Diagnosis was confirmed via urinary organic acid analysis and genetic testing. This case highlights that stress-induced hyperglycemia in inborn errors of metabolism such as organic acidemias and ketolytic defects can mimic diabetic ketoacidosis.