The human body is made up of cells. Each cell is a small factory that produces the material the body needs to develop. All cells contain a nucleolus, in which genes are stored. Genes are grouped into twisted structures of DNA called chromosomes. Usually the nucleus of each cell contains 23 pairs of chromosomes, 23 chromosomes we inherit from the mother and 23 from the father. Individuals with Down syndrome have 47 chromosomes, with an extra pair of 21 chromosomes. This extra genetic material causes Down Syndrome.
