Down syndrome (DS), also called Trisomy 21, is a condition in which extra genetic material causes delays in the way a child develops, both mentally and physically.

Down syndrome (DS) is one of the most common genetic birth disorders. Normally, each cell in the human body contains 23 pairs of chromosomes, which contain the genetic material that determines all our inherited characteristics. We receive half of each chromosome pair from our mother and the other half from our father. Individuals with Down syndrome, have an extra 21st chromosome.

Down syndrome occurs in approximately 1 of 830 live births. It is associated with mild to moderate learning disabilities, developmental delays, characteristic facial features, and low muscle tone in early infancy. Many individuals with Down syndrome also have heart defects, leukemia, early-onset Alzheimer's disease, gastro-intestinal problems, and other health issues. Through a series of screenings and tests, Down syndrome can be detected before and after a baby is born.

Though Down syndrome can't be prevented, it can be detected before a child is born. The health problems that may go along with DS can be treated, and many resources are available to help kids and their families who are living with the condition.

Life expectancy for individuals with Down syndrome has dramatically increased over the past few decades as medical care and social inclusion have improved. A person with Down syndrome in good health will on average live to age 55 or beyond.