A 7-month-old male presents with progressive weakness and profound hypotonia since 5 months of age. Vital signs: HR 120/min, RR 28/min, BP 85/55 mmHg, temperature 37°C, SpO2 98% on room air. Examination reveals absent deep tendon reflexes and preserved sensation. Serum creatine kinase is normal at 95 U/L. Genetic testing confirms degeneration of anterior horn cells. Which of the following mutations is most likely responsible for this neuromuscular disorder?

  1. A)Dystrophin frameshift mutation
  2. B)CTG repeat expansion in DMPK
  3. C)Dystrophin in frame mutation
  4. D)PMP22 duplication
  5. E)SMN1 deletionGABARITO

Explicação

Loss of SMN1 causes spinal muscular atrophy by impairing survival of motor neurons in the anterior horn. This leads to progressive lower motor neuron weakness beginning in infancy or childhood. Ver explicação completa e trilha adaptativa →

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