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El papel de TBX1 en el síndrome del22q11.2 humano
Hisato Yagi1, Yoshiyuki Furutani, Hiromichi Hamada
1Division of Genomic Medicine, Institute of Advanced Biomedical Engineering and Science, Graduate School of Medicine, Tokyo Women's Medical University, Tokyo, Japan.
Lancet (London, England)
|October 31, 2003
Resumen
Las deleciones en el cromosoma 22q11.2 causan un síndrome de microdeleción común. Las mutaciones del gen TBX1 se identifican como una causa genética significativa para este síndrome, incluso sin la deleción completa.
Área de la Ciencia:
- Genética La genética.
- Biología Molecular Biología Molecular
- Enfermedades humanas Enfermedades humanas.
Sus antecedentes:
- El síndrome de deleción 22q11.2 es un síndrome de microdeleción frecuente que afecta a 1 de cada 4000-5000 nacidos vivos.
- Caracterizado por defectos cardíacos, déficits de células T, paladar hendido, anomalías faciales e hipocalcemia, implica una deleción de 3 Mb en el cromosoma 22q11.2 con numerosos genes mapeados.
- El papel preciso de estos genes en la causa del síndrome sigue sin estar claro.
Objetivo del estudio:
- Para investigar la base genética del síndrome de deleción 22q11.2.
- Determinar si las mutaciones en el gen TBX1 contribuyen al fenotipo del síndrome, particularmente en individuos sin la deleción típica.
Principales métodos:
- El análisis de hibridación in situ de fluorescencia (FISH) utilizando diez sondas en 22q11.2 se realizó en 235 pacientes con diagnóstico del síndrome del22q11.2.
- El análisis genético de la secuencia de codificación TBX1 se realizó en 13 pacientes que exhibían el fenotipo del síndrome 22q11.2, pero carecían de una deleción detectable.
Principales resultados:
- Se confirmó una eliminación definida de 1.5-3-Mb en 22q11.2 en el 96% (225/235) de los pacientes.
- Se identificaron tres mutaciones de TBX1 en dos pacientes no relacionados sin la deleción 22q11.2, que presentaban una anomalía conotruncal cara / síndrome velocardiofacial o síndrome de DiGeorge.
- Estas mutaciones también se encontraron en tres pacientes de una familia con anomalía conotruncal cara / síndrome velocardiofacial y estuvieron ausentes en 555 controles sanos (p <0.0001).
Conclusiones:
- Las mutaciones de TBX1 están implicadas en la causa de cinco fenotipos principales asociados con el síndrome de deleción 22q11.2.
- El estudio concluye que TBX1 es un determinante genético crítico para el síndrome de deleción 22q11.2.
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