Down syndrome is a genetic disorder occurs when part of chromosome 21 gets attached to another chromosome during the formation of reproductive cells. This results in trisomy of 21 meaning each cell in body has 3 copies of chromosome 21. This additional genetic material alters the course of development.
Children suffering from Down syndrome show certain features such as flat face, a short neck, slating eyes and small mouth. They also have small degree of intellectual disability. Varied level of changes is seen in the development of brain and body develops.