Designed by: Sora Ahn
Children with Down syndrome have a distinct facial appearance. Though not all children with Down syndrome have the same features, some of the more common features are:
- Flattened facial features
- Small head
- Short neck
- Protruding tongue
- Upward slanting eyes, unusual for the child's ethnic group
- Unusually shaped ears
Infants with Down syndrome may be of average size, but typically they grow slowly and remain shorter than other children of similar age. In general, developmental milestones, such as sitting and crawling, occur at about twice the age of children without impairment. Children with Down syndrome also have some degree of mental retardation, most often in the mild to moderate range.
Some parents have a greater risk of having a baby with Down syndrome. Risk factors include:
- Advancing maternal age. A woman's chances of giving birth to a child with Down syndrome increase with age because older eggs have a greater risk of improper chromosome division. By age 35, a woman's risk of conceiving a child with Down syndrome is 1 in 400. By age 45, the risk is 1 in 35. However, most children with Down syndrome are actually born to women under age 35 because younger women have far more babies.
Down syndrome occurs in about 1 in 830 newborns. An estimated 250,000 people in the United States have this condition. Although women of any age can have a child with Down syndrome, the chance of having a child with this condition increases as a woman gets older.
When does it appear?
Chromosomal abnormalities such as Down syndrome can often be diagnosed before birth by analyzing cells in the amniotic fluid or from the placenta. Fetal ultrasound during pregnancy can also give information about the possibility of Down syndrome, but ultrasound is not 100 percent accurate, since many babies with Down syndrome may look the same on ultrasound as those without Down syndrome. A chromosome analysis, whether performed on a blood sample, cells from the amniotic fluid, or placenta, is over 99.9 percent accurate.
Where does it come from?
Ninety-five percent of Down syndrome results from trisomy 21. Occasionally, the extra chromosome 21 is attached to another chromosome in the egg or sperm; this may result in what is called "translocation" Down syndrome (3 to 4 percent of cases). This is the only form of Down syndrome that can sometimes be inherited from a parent.
To date, there is no reason to believe that a parent could have done anything to cause or prevent the birth of their baby with Down syndrome. However, a recent study suggests that some women who have had a baby with Down syndrome had an abnormality in how their bodies metabolize (process) the B vitamin folic acid. If confirmed, this finding may provide yet another reason why all women who might become pregnant should take a daily multivitamin containing 400 micrograms of folic acid (which has been shown to reduce the risk of certain birth defects of the brain and spinal cord).
Long-term effect on the person
Children with Down syndrome can usually do most things that any young child can do, such as walking, talking, dressing, and being toilet trained. However, they generally do these things later than other children. The outlook for these children is far brighter than it once was. Many will learn to read and write and participate in diverse childhood activities both at school and in their neighborhoods. While there are special work programs designed for adults with Down syndrome, many people with the disorder can hold regular jobs. Today, an increasing number of adults with Down syndrome live semi-independently in community group homes where they take care of themselves, participate in household chores, develop friendships, partake in leisure activities, and work in their communities. Some people with Down syndrome marry. Although there have been rare exceptions, men with Down syndrome cannot father a child. In any pregnancy, a woman with Down syndrome has a 50/50 chance of conceiving a child with Down syndrome, but many pregnancies are miscarried.
Treatment for Down syndrome focuses on making sure that the child has regular medical checkups, helping the child develop, watching for early signs of health problems, and finding support. With treatment and support, this can help the child live a happy, healthy life. There is no cure for Down syndrome. We are not certain how to prevent the chromosomal error that causes Down Syndrome. The March of Dimes is investigating why errors in chromosome division occur, in the hope of someday preventing Down syndrome and other birth defects caused by abnormalities in the number or structure of chromosomes. Other researchers are seeking to improve the outlook for children with Down syndrome. One example of this includes developing improved language intervention programs to help these children communicate more easily.