A 4-year-old boy presents with delayed motor milestones, frequent falls, and progressive difficulty rising from the floor. Vital signs: BP 95/60, HR 98, RR 20, Temp 37°C, SpO2 98%. Physical examination reveals bilateral calf pseudohypertrophy and a positive Gowers sign. Serum creatine kinase is markedly elevated at 8,500 IU/L. Cognitive examination is normal. Which of the following is the most likely diagnosis?

  1. A)Duchenne muscular dystrophyGABARITO
  2. B)Amyotrophic lateral sclerosis
  3. C)Becker muscular dystrophy
  4. D)Myotonic dystrophy
  5. E)Spinal muscular atrophy

Explicação

Duchenne muscular dystrophy is the correct answer because early childhood proximal weakness, calf pseudohypertrophy, and Gowers sign reflect severe dystrophin deficiency from an X-linked frameshift mutation. Ver explicação completa e trilha adaptativa →

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