One in every 691 babies born in the U.S. is born with
Down syndrome. About 400,000 people in the United States have Down syndrome, and approximately 6,000 babies are born each year with the disorder. Usually, children born with the condition have some degree of mental retardation, as well as characteristic physical features. Many of these children also have other health problems. Down syndrome may be diagnosed prenatally through screening and diagnostic tests. There is a specific pattern of cognitive and behavioral features that are observed among children with Down syndrome that differs from that seen in typically developing. Children with down syndrome might have smaller