Episodic myoglobinuria in a primary gamma-sarcoglycanopathy.

Episodic myoglobinuria is a well-recognized complication of metabolic myopathies, and may occur in Duchenne and Becker dystrophies, but has only rarely been associated with limb-girdle muscular dystrophy. We describe an unusual presentation, with rhabdomyolysis, of limb-girdle muscular dystrophy (LGMD). We evaluated a patient for progressive muscle weakness and tenderness, with myoglobinuria one week after initial presentation. Immunohistochemistry on muscle tissue revealed absent staining for gamma-sarcoglycan, confirmed by detection of a homozygous mutation in the gamma-sarcoglycan gene. Myoglobinuria has been previously reported only twice in LGMD. It is therefore important to recognize that myoglobinuria may be a symptom of a muscular dystrophy, and muscle biopsy and immunostaining are important tools for diagnosis.