Resumen
Introducción: el síndrome Prader-Willi (SPW) y el síndrome de Angelman (SA) son trastornos del neurodesarrollo producidos por deleciones o defectos de metilación que producen pérdida de expresión en los genes improntados de la región 15q11‑q13, mismos que pueden ser evaluados por diferentes técnicas citogenómicas y moleculares. Presentamos una serie de pacientes con SPW y SA en los que se identificó el tipo de defecto de la región 15q11-q13 mediante la técnica de MS-MLPA.
Casos clínicos: estudiamos cuatro pacientes con diagnóstico clínico de SPW y uno con SA, evaluados en lo posible con cariotipo, FISH y todos con ensayo MS-MLPA para la región 15q11-q13. En los pacientes con SPW, la hipotonía neonatal fue el motivo principal de consulta. En tres de ellos se identificó deleción de 15q11-q13 por MS-MLPA, confirmada por FISH, y en uno el patrón de metilación anormal fue compatible con una disomía uniparental materna. El paciente con SA presentó un cuadró típico y también se identificó una deleción en 15q11-q13 por MS-MLPA, confirmada por FISH.
Conclusiones: confirmamos que el uso de la técnica de MS-MLPA para la región 15q11‑q13 mostró ser de gran utilidad para identificar los mecanismos genómicos y epigenéticos implicados en el SPW y el SA.
Abstract
Background: Prader Willi syndrome (PWS) and Angelman syndrome (AS) are neurodevelopmental disorders caused by deletions or methylation defects, making a loss of expression of imprinted genes located in the 15q11-q13 region, and these can be assessed by different cytogenomic and molecular techniques. We report a case series of patients with PWS and AS evaluated through the MS-MLPA assay.
Clinical cases: We studied four patients with a clinical diagnosis of PWS and another with AS, evaluated as far as possible with karyotype and FISH, and with MS-MLPA assay for the 15q11-q13 region in all cases. In patients with PWS, neonatal hypotonia was the main reason for consultation and in three of them we identified a deletion of 15q11-q13 by MS-MLPA, also confirmed by FISH; and in the other one, an abnormal methylation pattern consistent with a maternal uniparental disomy. The patient with AS presented with a typical picture which led to the identification of a deletion in 15q11-q13 by MS-MLPA, also confirmed by FISH.
Conclusions: The use of the MS-MLPA assay for the 15q11-q13 region was very useful for the diagnosis and identification of the genomic and epigenetic defects involved in either PWS and AS.
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