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Defectos en RGS9 o su proteína ancla R9AP en pacientes con desactivación lenta de los fotorreceptores

Koji M Nishiguchi¹, Michael A Sandberg, Aart C Kooijman

¹Ocular Molecular Genetics Institute, Harvard Medical School, Massachusetts Eye and Ear Infirmary, Boston, Massachusetts 02114, USA.

|January 1, 2004

Resumen

Las proteínas RGS9 y R9AP son cruciales para la visión. Las mutaciones en estos genes causan bradyopsia, una condición caracterizada por una alteración de la adaptación a la luz y una capacidad reducida para ver objetos en movimiento.

Área de la Ciencia:

Biología Molecular Biología Molecular
La neurociencia es la neurociencia.
Oftalmología Oftalmología.

Sus antecedentes:

Las proteínas reguladoras de la señalización de la proteína G (RGS) modulan las vías de señalización de los eucariotas.
RGS9, anclado por la proteína de anclaje RGS9 (R9AP), es vital para la fototransducción en las células de bastón y cono.
La deficiencia en la interacción RGS9-R9AP retrasa la recuperación de la respuesta a la luz en ratones.

Objetivo del estudio:

Para investigar el fenotipo humano asociado con mutaciones en los genes RGS9 o R9AP.
Para identificar la base genética de las deficiencias visuales relacionadas con la fototransducción.

Principales métodos:

Análisis genético de cinco pacientes no relacionados con déficits visuales.
Examen clínico que incluye la agudeza visual, los campos visuales y la evaluación de la sensibilidad al contraste.
Correlación fenotípica con las mutaciones genéticas RGS9 y R9AP.

Principales resultados:

Se identificaron cinco pacientes con mutaciones recesivas en RGS9 o R9AP.
Los pacientes presentaron bradyopsia: dificultad para adaptarse a los cambios de luminancia y mala detección de movimiento de bajo contraste.
La agudeza visual estándar y los campos visuales se conservaron en gran medida.

Conclusiones:

Las mutaciones humanas en RGS9 o R9AP causan bradyopsia, un nuevo trastorno visual.
Este estudio identifica el primer fenotipo humano vinculado a la reducción de la actividad de la proteína RGS en cualquier órgano.
Destaca el papel crítico de RGS9-R9AP en la adaptación visual mediada por el cono y la percepción del movimiento.

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