Cytogenetic Profile in 1,921 Cases of Trisomy 21 Syndrome

摘要

Background and Aims. Trisomy 21 is the most frequent genetic cause of intellectual disability. It is caused by different cytogenetic aberrations: free trisomy, Robertsonian translocations, mosaicism, duplication of the critical region and other structural rearrangements of chromosome 21. The aim of the study was to identify in Mexican trisomy 21 patients who attended Hospital Infantil de Mexico Federico Gomez from 1992-2011 the type and frequency of the cytogenetic aberration and to evaluate the effect of maternal age.