Atrofia muscular espinal: aspectos clínicos, genéticos y alternativas terapéuticas
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Palabras clave
Atrofia Muscular Espinal, Enfermedades Raras, Terapia Genética, Proteína de Supervivencia de las Neuronas Motoras
Resumen
La atrofia muscular espinal (AME) es un trastorno neuromuscular causado por una mutación en el gen SMN1, localizado en el cromosoma 5q13. Se caracteriza fundamentalmente por una degeneración neuronal por deficiencia en la producción de la proteína de supervivencia de las neuronas motoras de longitud completa (FL-SMN), lo que ocasiona debilidad muscular progresiva con complicaciones como escoliosis, parálisis e incluso la muerte. En este artículo se revisan los aspectos clínicos y genéticos de la enfermedad, su diagnóstico y clasificación, así como las alternativas terapéuticas. En este contexto, resalta el papel que tiene la determinación molecular de la variante genética causal, así como del número de copias del gen homólogo SMN2 como principal modificador del curso de la enfermedad, tanto para el diagnóstico y la clasificación, como para la toma de decisiones terapéuticas. Recientemente, se han desarrollado terapias enfocadas en modificar la historia natural de la AME mediante el aumento de la producción de la proteína FL-SMN. Actualmente se encuentran disponibles 3 tratamientos: Spinraza (nusinersen), Zolgensma (onasemnogén abeparvovec) y Evrysdi (risdiplam). Los estudios realizados con estos fármacos para confirmar su seguridad y eficacia muestran resultados favorables; no obstante, un diagnóstico temprano es decisivo para el éxito de cualquiera de estas alternativas terapéuticas.
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