In humans, there are a total of 23 pairs of chromosomes in each of our cells. People with Down Syndrome, however, are born with an extra copy of chromosome 21.
Because of this third copy, this condition is also often referred to as Trisomy 21. This abnormality in the number of chromosomes is the most common cause of:
- significant mental retardation
- delayed learning ability in children
Children born with this condition are also likely to develop heart, hearing and visual defects at birth or as they age. With the help of stimulation programs and proper health care, people with Down Syndrome can lead a healthy life and live up to 45-50 years old. Though it happens randomly, can occur at any age, and is rarely passed on from the parent’s genes, the risk becomes significantly higher in older mothers.
About 1 in 1,000 babies is born with Down’s syndrome.