Down Syndrome (Trisomy 21)


This is a condition a baby is born with. It's caused by an extra bundle of genetic information, called a "chromosome," in the body's cells. Down syndrome affects the body and the brain.

What causes it?

What causes Down syndrome? Well, it happens when cells form and divide to create a baby. The instructions for these cells are packed into pairs of chromosomes. Normally, each parent gives half of every chromosome pair. But with Down syndrome, there's an extra copy of one chromosome. The extra copy can come from one of the parents. Or, it can be made when the baby's cells don't divide properly. A baby's risk for Down syndrome is higher if the mother is age 35 or older.


People with Down syndrome often have similar physical features. They may have features like a flattened face, almond-shaped eyes and small ears. They are often shorter than other people. Down syndrome is linked to heart defects, eye diseases and other problems. And, Down syndrome also leads to challenges with intellect and with speech. But different people have different abilities. Every person with Down syndrome is unique.

Managing Down syndrome

Down syndrome is a lifelong condition. But it can be managed successfully. Speech therapy, physical therapy and occupational therapy can help. Children with Down syndrome benefit from more attention in school. A local Down syndrome organization can help you learn about resources available to you. Talk to your doctor for more information.