Cytogenetic features of children with Down syndrome

Down syndrome (DS) (trisomy, trisomy on chromosome 21) - "... this is a genetic abnormality in development and the most common chromosomal anomaly affecting mental development and mental development with a statistical occurrence of 1 in 700-800 newborns" [19,22,42 ]. There is no gender difference in the incidence of DM, it is stated regardless of the ethnic group, race and economic class of the family. The concept of "syndrome" defines the presence of specific signs or traits characteristic of a particular condition, so this pathology is commonly referred to as the term "Down's syndrome" and not "Down's disease" [1,38].