Severe rhabdomyolysis in an infant due to fatty acid oxidation disorder: a case report.

Background: Rhabdomyolysis can develop from numerous etiologies, both acquired and hereditary. Consequences of rhabdomyolysis may be grave, therefore identifying and treating the etiology is crucial.

Case presentation: We herein report the occurrence of severe rhabdomyolysis in a previously healthy 14-month-old infant presenting to the emergency department with fever, hypotonia, and generalized discomfort. Analysis revealed extremely high creatine phosphokinase levels (> 100,000 UI/L). Metabolic myopathy was suspected, however, primary metabolic analyses were normal. Carnitine palmitoyltransferase II deficiency was diagnosed following genetic analysis, identifying a homozygous NM_000098.3, c.338C > T, p.[Ser113Leu] missense variant. Prophylactic measures were established to prevent relapse and genetic counseling provided for the sibship.

Conclusion: This case highlights the difficulty of diagnosing carnitine palmitoyltransferase II deficiency in an infant and the importance of genetic analysis to establish the diagnosis, despite a normal acylcarnitine profile.