Unraveling the culprit behind the exercise-induced recurrent rhabdomyolysis in a young adult

ABSTRACT

Background: Recurrent rhabdomyolysis induced by exercise or physical exertion in a healthy young individual is uncommon and necessitates further investigations of an underlying disorder. Metabolic myopathy is one of the rare causes of recurrent rhabdomyolysis in adolescents and adults. Clinical parameters are normal in between the episodes in which patients remain asymptomatic. The acylcarnitine profiles provide a significant clue to diagnosis.

Case: We present a case of a young adult female who presented with recurrent exercise-induced rhabdomyolysis. The appropriate diagnosis was established two years after the onset of the first episode of her seemingly uneventful rhabdomyolysis. Her signs and symptoms including her acylcarnitine profile were similar to a long-chain fatty acid oxidation disorder (LC-FAOD). However, genetic analysis showed a missense mutation of RYR1 that has never been reported before. After fatty diet restriction, she has not reported rhabdomyolysis since.

Conclusion: Due to the unpredictable nature of symptomatology, the diagnosis and management of metabolic myopathy should be approached carefully. An inconclusive acylcarnitine profile must be confirmed with genetic analysis.

Keywords: Rhabdomyolysis, acylcarnitine, metabolic myopathy, RYR1