A 17-year-old boy presents with severe muscle cramps and dark urine following intense basketball practice. Vital signs show BP 118/76, HR 102, RR 18, temp 37.2°C, SpO2 98%. Serum creatine kinase is 850 U/L with myoglobin detected in urine. He denies proximal weakness or family history of similar episodes. Symptoms resolve after brief rest, allowing him to resume activity at reduced intensity without recurrence. Which enzyme deficiency best explains this clinical presentation?
- A)Acid maltase deficiency
- B)Hexosaminidase A deficiency
- C)Muscle glycogen phosphorylase deficiencyGABARITO
- D)Ornithine transcarbamylase deficiency
- E)Galactocerebrosidase deficiency
Explicação
McArdle disease is due to deficiency of muscle glycogen phosphorylase and causes exercise intolerance, cramps, and myoglobinuria. A second wind phenomenon may occur after brief rest as muscles rely more on alternative energy sources. Ver explicação completa e trilha adaptativa →