Down syndrome is a condition in which a person is born with an extra copy of chromosome 21. People with Down syndrome can have physical problems, as well as intellectual disabilities. Every person born with Down syndrome is different.
People with the syndrome may also have other health problems. They may be born with heart disease. They may have dementia. They may have hearing problems and problems with the intestines, eyes, thyroid, and skeleton.
The chance of having a baby with Down syndrome increases as a woman gets older. Down syndrome cannot be cured. Early treatment programs can help improve skills. They may include speech, physical, occupational, and/or educational therapy. With support and treatment, many people with Down syndrome live happy, productive lives.
What is Down Syndrome?
Down syndrome is a condition in which a person has an extra chromosome. Chromosomes are small “packages” of genes in the body. They determine how a baby’s body forms during pregnancy and how the baby’s body functions as it grows in the womb and after birth. Typically, a baby is born with 46 chromosomes. Babies with Down syndrome have an extra copy of one of these chromosomes, chromosome 21. A medical term for having an extra copy of a chromosome is ‘trisomy.’ Down syndrome is also referred to as Trisomy 21. This extra copy changes how the baby’s body and brain develop, which can cause both mental and physical challenges for the baby.
Even though people with Down syndrome might act and look similar, each person has different abilities. People with Down syndrome usually have an IQ (a measure of intelligence) in the mildly-to-moderately low range and are slower to speak than other children.
Some common physical features of Down syndrome include:
- A flattened face, especially the bridge of the nose
- Almond-shaped eyes that slant up
- A short neck
- Small ears
- A tongue that tends to stick out of the mouth
- Tiny white spots on the iris (colored part) of the eye
- Small hands and feet
- A single line across the palm of the hand (palmar crease)
- Small pinky fingers that sometimes curve toward the thumb
- Poor muscle tone or loose joints
- Shorter in height as children and adults
How Common is Down Syndrome?
According to the Centers for Disease Control and Prevention, approximately one in every 700 babies in the United States is born with Down syndrome, making Down syndrome the most common chromosomal condition. About 6,000 babies with Down syndrome are born in the United States each year.