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Una nueva variante tRNASer(AGY) 12244G > a altera la función mitocondrial y se presenta con un fenotipo clásico de
Xingyu Zhuang1, Jiayin Wang1, Jianing Wang1
1Department of Neurology, Shandong Key Laboratory of Mitochondrial Medicine and Rare Diseases, Research Institute of Neuromuscular and Neurodegenerative Diseases, Qilu Hospital of Shandong University, Jinan, Shandong, China.
Resumen
Una variante rara del ADN mitocondrial, m.12244G>A en el gen MT-TS2, causa MELAS (encefalopatía mitocondrial, acidosis láctica y episodios similares a un ictus) al alterar la función y la traducción mitocondrial.
Área de la Ciencia:
- Genética
- Biología Molecular
- Bioquímica
Sus antecedentes:
- Los trastornos mitocondriales son enfermedades complejas que afectan la fosforilación oxidativa (OXPHOS).
- MELAS (encefalopatía mitocondrial, acidosis láctica y episodios similares a un ictus) es un subtipo común causado a menudo por variantes del gen del ARNt mitocondrial.
- Los mecanismos precisos de muchas variantes asociadas a MELAS no se comprenden completamente.
Objetivo del estudio:
- Investigar la patogenicidad de una variante rara m.12244G>A en el gen MT-TS2.
- Dilucidar los mecanismos moleculares subyacentes al efecto de la variante en la función mitocondrial.
- Ampliar la comprensión de las correlaciones genotipo-fenotipo en MELAS.
Principales métodos:
- Evaluación clínica integral, pruebas genéticas y análisis de tejido muscular (histopatología, ensayos bioquímicos) de un paciente.
- Evaluaciones funcionales de la traducción mitocondrial y la OXPHOS.
- Revisión sistemática de la literatura de variantes de MT-TS2 y fenotipos asociados.
Principales resultados:
- Identificada la variante m.12244G>A en el gen tRNASer(AGY), relacionada con un fenotipo clásico de MELAS.
- Demostrada alteración de la traducción mitocondrial y disfunción de la OXPHOS debido a la variante.
- Observadas fibras COX-negativas, fibras rojas irregulares y niveles reducidos de proteínas mitocondriales; la revisión de la literatura reveló fenotipos diversos para las variantes de MT-TS2.
Conclusiones:
- Se proporcionó validación experimental de la patogenicidad de la variante m.12244G>A.
- Se confirmó el impacto perjudicial de la variante en la función mitocondrial.
- Se ampliaron las causas genéticas conocidas de MELAS y se enfatizó la necesidad de estudios funcionales de variantes del ADNmt.
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