Abstract

Aim: The aim of this research was to ascertain the frequency of three basic cytogenetical types of Down syndrome among Kosova Albanian population and to evaluate the maternal age effect on the frequency of births of children with Down syndrome. Methods: Cytogenetics diagnosis has been made according to the standard method of Moorhead and Seabright. Results: In the time period 2000-2010 cytogenetics diagnosis of overall 305 children with Down syndrome has been realized. Of which in 285 children (93.4%) were found free trisomy 21 (regular type), and in three other children (~1.0%) were detected mosaic trisomy 21. Translocation trisomy 21 was detected in 17 children (5.6%), of which in 14 children it occurred de novo translocation, whereas in 3 other children translocation has been inherited by a parent translocation carrier. The highest number of children with Trisomy 21 due to translocation was caused by Robertsonian translocation created by a fusion of two homologous chromosomes 21 (3.3%). Analysis showed that the number of children born with Down’s syndrome, from 2000 to 2010, was not decreasing among the Kosova Albanian population. Conclusion: Down syndrome resulted by an extra free chromosome 21 is the most common genetic cause for that condition. Robertsonian translocations present in Down syndrome children often are de novo or inherited from a carrier parent with translocation.

Key words: Down syndrome, free trisomy 21, Robertsonian translocation.