What Is Down Syndrome?
What is Down Syndrome?
Down's syndrome is the most common cause of mental retardation (see mental retardation entry) and malformation in newborns. It occurs because of the presence of an extra chromosome.
Chromosomes are structures that carry genetic information in cells. They carry the instructions that tell cells what functions they are to perform. They determine the way a person's body looks and the way it functions.
Cells normally carry two matched sets of twenty-three chromosomes for a total of forty-six chromosomes. One set of twenty-three chromosomes comes from each parent. Down's syndrome occurs when one chromosome pair is damaged. That pair is designated as chromosome #21.
Copyright Â© 2007 - Advameg Inc.