(SBQ13PE.2)
A 12-month-old male presents with symmetric, progressive weakness that is more profound in lower extremity than upper extremity. On physical exam, he can sit but cannot walk. He has tongue fasciculations and absent deep tendon reflexes. Serum creatine phosphokinase and aldolase levels are normal. Which of the following genetic mutations or deletions is responsible for his condition?
QID:
4915