[Gastrointestinal obstruction in the mosaic trisomy X].

Trisomic X is a sex chromosomal abnormality that may be presented in mosaic. This is not extremely rare, the majority of cases go undiagnosed. The prevalence has been established to 1/1000 females.

[Frequency of imperforate anus and associated risk factors in patients with Down syndrome].

Objectives: To establish the frequency of imperforate anus (IA) in the population with Down syndrome (DS) and study the associated risk factors.

Methods: An observational clinical study case control type was performed. The patients were evaluated at the Unit of Medical Genetics, University of the Andes, from February 2006 to February 2011.