Rhabdomyolysis and Exercise Intolerance in a 45-Year-Old Man

A 45-year-old man presented to neuromuscular clinic after a first-time episode of non-traumatic rhabdomyolysis after aerobic exercise. Prior to his diagnosis, he had an extensive medical workup to evaluate for elevated transaminases and creatinine, including liver and renal biopsies. On history, the patient confirmed a lifelong history of exercise intolerance. Creatine kinase evaluation revealed an elevated baseline value. Genetic testing disclosed homozygous variants of uncertain significance and required exercise testing and muscle biopsy to identify the underlying etiology. This case demonstrates pitfalls of genetic testing and an approach to identify this form of myopathy.