RESUMEN
Complex genomic rearrangements (CGRs) consisting of two or more breakpoint junctions have been observed in genomic disorders. Recently, a chromosome catastrophe phenomenon termed chromothripsis, in which numerous genomic rearrangements are apparently acquired in one single catastrophic event, was described in multiple cancers. Here, we show that constitutionally acquired CGRs share similarities with cancer chromothripsis. In the 17 CGR cases investigated, we observed localization and multiple copy number changes including deletions, duplications, and/or triplications, as well as extensive translocations and inversions. Genomic rearrangements involved varied in size and complexities; in one case, array comparative genomic hybridization revealed 18 copy number changes. Breakpoint sequencing identified characteristic features, including small templated insertions at breakpoints and microhomology at breakpoint junctions, which have been attributed to replicative processes. The resemblance between CGR and chromothripsis suggests similar mechanistic underpinnings. Such chromosome catastrophic events appear to reflect basic DNA metabolism operative throughout an organism's life cycle.
Asunto(s)
Aberraciones Cromosómicas , Reparación del ADN , Discapacidades del Desarrollo/genética , Neoplasias/genética , Secuencia de Bases , Niño , Preescolar , Rotura Cromosómica , Hibridación Genómica Comparativa , Replicación del ADN , Femenino , Humanos , Hibridación Fluorescente in Situ , Lactante , Masculino , Datos de Secuencia MolecularRESUMEN
Introducción. Objetivo: evaluar el cumplimiento de la "Guía de salud para personas con síndrome de Down" de la Asociación Americana de Pediatría de 2001 en pacientes del Departamento de Genética del Hospital Universitario "Dr. José Eleuterio González . Métodos. Estudio retrospectivo, descriptivo, observacional y transversal, en el cual se revisaron los expedientes de pacientes con síndrome de Down que acudieron a consulta al Departamento de Genética entre abril de 2004 y abril de 2006. Resultados. Se identificaron 38 casos. El límite de edad materna fue de 17-43 años. En 74% de los pacientes se realizó cariotipo y sólo 61% recibieron asesoría genética. Se identificó cardiopatía congénita por ecocardiograma en 26%, pero en 56% no se realizaron estudios a pesar de contar con datos clínicos sugestivos. El número máximo de consultas fue de 5; sin embargo, 44% de los pacientes no tuvo seguimiento. Conclusiones. Se identificó una falla importante en la adherencia al seguimiento y a la realización de estudios encaminados a descartar las complicaciones asociadas al síndrome.
Introduction. Objective: To evaluate the application of the American Academy of Pediatrics' "Guidelines for health supervision for children with Down syndrome" in the Department of Genetics at the Hospital Universitario "Dr. José Eleuterio González". Methods. We analyzed clinical files from all Down's syndrome patients who attended our Department of Genetics from April 2004 to April 2006. Results. Thirty-eight cases were identified. The rank of mothers' age at date of infant birth was 17-43 years old; 74% of the patients had a karyotype performed, but genetic counseling was given only to 61% of families. An echocardiogram was performed; congenital heart disease was detected in 26%, but 56% did not attend the cardiologist consultation even when some of them had clinical findings suggesting heart disease. At the end of the study, the highest number of consultations was 5; however, 44% of the patients had no follow-up. Conclusions. We found a significant lack of commitment to follow-up patients by care givers, and a delay to accomplish clinical studies to avoid the well-known complications associated to this syndrome.
