Malformation Variability Associated to Chromosome Trisomies. Clinical and Phenotipical Implications in Several Patients at a Pediatric Hospital in Mexico

Chromosome trisomies are considered alterations in the chromosome number or structure. A trisomy is therefore a type of polysomy in which there are three chromosome copies, instead of the normal two. A trisomy is considered an aneuploidy or abnormal number of chromosomes. There are two different trisomy types; Full trisomy" where an entire extra chromosome has been copied. "Partial trisomy" means that there is an extra copy of part of a chromosome. Depending on the chromosome, a trisomy is named as “Autosomal trisomies" (trisomies of the non-sex chromosomes) and "Sex-chromosome trisomies." In this study both Autosomal and Sex-chromosome trisomies are described in differents patients, depending on the affected chromosome. Among 4617 chromosomal studies performed during 19 years (from 1992 to 2011), at Hospital Para el Niño Poblano in México, 34.6% (1596 patients) had chromosomal alterations. Among these studies population, a male and female pediatric patients are described, with different chromosome trisomies, were chromosome changes are classified as structural or numeric alterations. All trisomies patients were described in this study analyzing their phonotypical and clinical features, medical treatments and prognosis.