Recurrent rhabdomyolysis caused by carnitine palmitoyltransferase II deficiency, common but under-recognised: Lessons to be learnt

We discuss two adult siblings who presented with symptoms of myalgia and rhabdomyolysis following exercise with myoglobinuria; genetic testing confirmed carnitine palmitoyltransferase II deficiency and resulted in institution of appropriate crisis management and dietary advice. We explore the phenotypic variability of this commonest fatty oxidation defect that remains under-diagnosed in the adult population and provide clues for early recognition and diagnosis.
Highlights • CPT II deficiency should be considered as an important differential diagnosis in individuals presenting with recurrent or even single attacks of muscle weakness. • If the clinical history includes ‘unexplained’ rhabdomyolysis, clinicians should have a low threshold to perform plasma acylcarnitine analysis as a first line investigation, especially in the context of elevated CK. • Confirmatory diagnosis is by identification of disease-causing variants in CPT2 through targeted testing. • It is important that these individuals have specialist dietary advice and annual monitoring.