Behavioral Patterns in Children with Down Syndrome

Down syndrome is a "set of mental and physical symptoms that result from having an extra copy of chromosome 21" (www.nlm.nih.gov). In other words, it is set of physical, mental and behavioral characteristics that are due to a specific genetic abnormality. It was in 1866 that a physician named John Langdon Down published an essay in England in which he described a group of children possessing common traits that differed from other children with mental retardation (Leshin, 2003). In the beginning, children with Down syndrome were referred as "mongoloids" because they looked like people from Mongolia but as this brought up later conflicts among Asian researchers, the term was changed (upon the name of the physician) to Down's syndrome (Leshin).

In 1959, Jerome Lejeune and Patricia Jacobs, working independently, were the first to determine that the cause of the syndrome is trisomy (triplication) of the 21st chromosome (Leshin, 2003). Specifically, every cell in the human body contains genetic material stored in genes that carry inherited traits which are grouped in structures called chromosomes. The nucleus of each cell contains 23 pairs of chromosomes, half of which are inherited from each parent. Down syndrome is caused when an embryo has three copies of chromosome 21 instead of the usual two (www.ndss.org). This supplemental chromosome 21 changes the embryo's development and causes the characteristics associated with Down syndrome.

People with Down syndrome share certain physical and mental features; however, symptoms may vary from mild to harsh with mental and physical development being slower in children with Down syndrome than in those without it (www.nlm.nih.gov). The common features that those people share, involve flattened face and nose, short neck, a small mouth sometimes with a large tongue, small ears, upward eyes that may have small skin folds at the inner corner, probably white spots on the iris, short, broad hands with short fingers with a single crease in the palm and poor muscle tone (www.medicinenet.com).

Apart from the observable physical characteristics, children with Down syndrome have an increased risk for various medical states such as heart defects, hearing problems, Alzheimer's disease, leukemia, and thyroid conditions (www.ndss.org). Furthermore, they experience cognitive delays and difficulties in developing basic language