Down syndrome is a chromosomal anomaly which usually causes delays in physical and intellectual development. Children with Down syndrome are not defective, they are just different. For some unexplained reason, an error in cell development results in forty-seven chromosomes rather then the normal forty-six. The extra gene material slightly changes the orderly development of the body and the brain. There are about 6,000 babies born with Down syndrome each year in the United States. There are thousands more born throughout the world. The national population of individuals with Down syndrome is estimated to be around 250,000. The exact cause and prevention of Down syndrome is unknown.
Well before the genetic link to Down syndrome was discovered, John Lagdon Down described it in 1866 as a distinct set of characteristics. He distinguished Down syndrome from other conditions by noting some of the common features associated with it, such as thin, straight hair, a small nose, and a broad face. Down is also credited with naming the condition "mongolism. It was called this because most infants with this condition have a somewhat Oriental appearance. This term is no longer used and we refer to t