Acute Kidney Injury and Extreme Rhabdomyolysis due to Carnitine Palmitoyltransferase II Deficiency: A Case Report.

BACKGROUND: Carnitine palmitoyltransferase II (CPT II) deficiency is a rare inherited disorder of long-chain fatty acid oxidation that may present in adulthood with episodic myopathy and rhabdomyolysis. Severe episodes can be life-threatening and may result in acute kidney injury (AKI), particularly when triggered by infection or metabolic stress. CASE REPORT: A 47-year-old male presented to the emergency department with influenza-like symptoms and rapidly developed extreme rhabdomyolysis (creatine kinase >126,800 IU/L) and acute kidney injury requiring renal replacement therapy. Dark-colored urine, metabolic acidosis, and multiorgan dysfunction were observed. Continuous renal replacement therapy was initiated in the intensive care unit, resulting in gradual clinical improvement. A detailed family history prompted genetic testing, which revealed a homozygous pathogenic CPT2 mutation (p.Ser113Leu), confirming stress-induced myopathic CPT II deficiency. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: This case emphasizes that inherited metabolic myopathies should be considered in patients presenting with unexplained, extremely elevated creatine kinase levels and acute kidney injury, particularly in the setting of infectious triggers. Early recognition and prompt supportive management in the emergency department are essential to prevent morbidity and mortality.