Acute kidney injury after swimming: a pediatric case of McArdle disease.

McArdle disease, a rare metabolic disorder, can lead to muscle breakdown and acute kidney injury (AKI) following physical exertion. We report a 12-year-old girl who developed AKI after several hours of swimming. Laboratory findings showed elevated blood urea nitrogen, creatinine, and creatine phosphokinase levels, indicating myoglobinuria. Genetic testing confirmed a pathogenic c.1708C > T mutation in the PYGM gene, diagnosing McArdle disease. After four sessions of hemodialysis, her kidney function fully recovered. This case highlights the need to consider metabolic disorders in the differential diagnosis of AKI, even following moderate exercise, and underscores the role of genetic testing in diagnosing rare conditions.