Repeated and progressive rhabdomyolysis due to a novel carnitine palmitoyltransferase II gene variant in an adult male: A case report

Abstract

Introduction:The occurrence of repeated and progressive rhabdomyolysis is rare in clinical settings, particularly in adults. The pathogenesis of rhabdomyolysis is often overlooked due to its rapid recovery. Carnitine palmitoyltransferase (CPT) II deficiency could be a rare etiology of repetitive nontraumatic rhabdomyolysis, and several mutations of CPT II have been reported.Patient concerns:A 41-year-old man presented with high fever, general malaise, myalgia, dyspnea, and dark-colored urine, and then progressed to anuria. In the past 15 years, he experienced dark-colored urine twice due to exercise and high fever. Physical examination revealed oliguria, suppurated tonsils, poor hemoglobin saturation, alert consciousness, normal neurological signs and reflexes, hypertension, and tachypnea. Laboratory investigations showed positive test results for inflammation, high serum myogenic enzyme levels, and evidence of acute kidney injury (AKI).Diagnoses:Investigations revealed an extremely high serum myogenic enzyme levels and impaired renal function with serum creatinine level of 510μmol/L, consistent with the diagnosis of rhabdomyolysis, AKI stage 3, and acute respiratory distress syndrome. High levels of acylcarnitine in the serum confirmed the diagnosis of CPT II deficiency. In addition, whole exome sequencing (WES) was conducted in the patient and his mother.Interventions:Intubation, ventilator support, and hemodialysis were the major therapeutic interventions at the peak of disease progression. He was then administered valsartan tablets at a dosage of 80mg per day and L-carnitine supplements.Outcomes:WES conducted in the patient and his mother revealed 2 novel mutations of CPT II (c.482G>A and c.1493G>T) in this patient. The patient recovered from the severe AKI but the renal function remained impaired at chronic kidney disease stage 3a.Conclusion:Thus, gene examination can help to understand the etiology of repetitive nontraumatic rhabdomyolysis. Accurate diagnosis can be beneficial for providing an individualized treatment for patients with repeated and progressive rhabdomyolysis.