Down syndrome is the most common and readily identifiable chromosomal condition associated with intellectual disabilities.

Down syndrome is a genetic disorder that occurs in approximately one of 800 live births. It is caused most often by an abnormality during cell division in gamete formation called nondysjunction. As a result, the fertilized egg will contain three copies of chromosome 21. The extra chromosome interferes with normal growth and development. Therefore, it is important for parents, health care professionals and teachers to have a clear and accurate understanding of each child's medical concerns and level of developmental functioning. In most cases, the diagnosis of Down syndrome is made according to results from a chromosome test administered shortly after birth. Although parents of any age may have a child with Down syndrome, the incidence is higher for women of advanced age (i.e., over 35 years of age).

There are over 50 clinical signs of Down syndrome, but it is rare to find all, or even most, of them in one person. 

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Learn more about Down syndrome treatment options at Kennedy Krieger by visiting our Down Syndrome Clinic and Research Center page:

Down Syndrome Clinic and Research Center

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