McArdle’s disease: A case of exercise intolerance and myopathy

ABSTRACT McArdle disease is a hereditary glycogen storage disorder caused by a deficiency in the enzyme myophosphorylase, leading to impaired glycogen breakdown in skeletal muscles. Muscle cramping, exercise intolerance, and the possibility of rhabdomyolysis are the outcomes of this. A 25-year-old male with a seven-year history of genetically confirmed McArdle disease presented with dark-colored urine and sharp left-sided chest pain after swimming and consuming 10 ounces of tequila. A physical examination revealed tachycardia, muscular weakness, and discomfort. Aspartate aminotransferase, alanine aminotransferase, and creatine kinase levels were high in the laboratory, indicating rhabdomyolysis. Analgesia and intravenous fluids were administered to the patient. Though it usually manifests in infancy, McArdle disease is often misdiagnosed, delaying a proper diagnosis until maturity. To avoid consequences such as acute renal failure and rhabdomyolysis, early detection is essential. Muscle biopsies may not be necessary when genetic testing helps with diagnosis. Nutritional therapies, activity avoidance, and patient education are all part of management. According to recent research, pre-exercise sugar consumption, aerobic training, and ketogenic diets enhance exercise tolerance and lessen muscle damage. This example emphasizes the need for early diagnosis and tailored treatment to improve results and quality of life.