Down syndrome is a chromosomal disorder that includes a combination of birth defects. Affected individuals have some degree of intellectual disability, characteristic facial features and, often, heart defects and other health problems. The severity of these problems varies greatly among affected individuals.
What health problems might a person with Down syndrome have? Some individuals with Down syndrome may have a number of these problems, while others may have none. The severity of these conditions varies greatly. What does a child with Down syndrome look like? Most children with Down syndrome have some, but not all, of these features. How serious is the intellectual disability? What can a child with Down syndrome do? The exact age that these developmental milestones are achieved cannot be predicted. However, early intervention programs beginning in infancy can help these children achieve their developmental milestones sooner. Can a child with Down syndrome go to school? While there are special work programs designed for adults with Down syndrome, many people with the disorder 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. Does the risk of Down syndrome increase with the mother’s age? Even though the risk is greater as the mother’s age increases, about 80 percent of babies with Down syndrome are born to women under age 35. This is because younger women have more babies than older women. What is the risk that parents of a child with Down syndrome will have another affected child? After birth, the provider takes a blood sample from a baby suspected of having Down syndrome and sends it to a laboratory. The lab does a karyotype (examines the chromosomes) to determine if the baby has Down syndrome and what genetic form of Down syndrome the baby has. This information is important in determining the risk in future pregnancies. The provider may refer parents to a genetic counselor who can explain the results of chromosomal tests in detail, including what the recurrence risks may be in another pregnancy. Can Down syndrome be diagnosed before the child is born? Women who have an abnormal screening test result are offered a diagnostic test, such as amniocentesis or chorionic villus sampling (CVS). These tests are highly accurate at diagnosing or, more likely, ruling out Down syndrome. ACOG also recommends that pregnant women of all ages have the option of bypassing the screening test and choosing a diagnostic test for Down syndrome instead. Until recently, only women over age 35 and others considered at increased risk for having a baby with Down syndrome were offered diagnostic testing because amniocentesis and CVS pose a small risk of miscarriage. In the future, screening for Down syndrome may be able to be accomplished with a simple blood test of the pregnant woman that can find and examine minute amounts of fetal genetic material. Most parents-to-be receive reassuring news from a screening or diagnostic test for Down syndrome. However, if a prenatal diagnostic test shows that the baby has Down syndrome, parents have an opportunity to consider the diagnosis and their options. They also can prepare medically, emotionally and financially for the birth of a child with special needs, such as arranging for delivery in a medically appropriate setting. Can people with Down syndrome have children?
Down syndrome is one of the most common genetic birth defects. It affects about 1 in 800 (about 3,400) babies a year in the United States. According to the National Down Syndrome Society, there are more than 400,000 individuals with Down syndrome in the United States.
The outlook for individuals with Down syndrome is brighter than it once was. Most of the health problems associated with Down syndrome can be treated, and life expectancy is now about 60 years. Individuals with Down syndrome are more likely than unaffected individuals to have one or more of the following health conditions:
A child with Down syndrome may have:
The degree of intellectual disability varies widely. Most affected individuals have intellectual disabilities within the mild to moderate range. With proper intervention, few affected individuals have severe intellectual disability. There is no way to predict the mental development of a child with Down syndrome based upon physical features.
Children with Down syndrome usually can do most things that any young child can do, such as walking, talking, dressing and being toilet-trained. However, they generally start learning these things later than unaffected children.
Yes. There are special programs beginning in the preschool years to help children with Down syndrome develop skills as fully as possible. Along with benefiting from early intervention and special education, many children are integrated into the regular classroom. Many affected children learn to read and write, and some graduate from high school and go on to post-secondary programs or college. Many individuals with Down syndrome participate in diverse childhood activities at school and in their neighborhoods.
There is no cure for Down syndrome. However, some studies suggest that women who have certain versions of some genes that affect how their bodies metabolize (process) the B vitamin folic acid may be at increased risk for having a baby with Down syndrome. 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. Taking folic acid can help reduce the risk of having a baby with certain birth defects of the brain and spinal cord.
Yes. The risk of Down syndrome increases with the mother’s age:
In general, in each subsequent pregnancy the chance of having another baby with Down syndrome is about 1 in 100 up to age 40. After age 40, the risk is based on the mother’s age. If, however, the first child has translocation Down syndrome, the chance of having another child with Down syndrome may be greatly increased.
Yes. The American College of Obstetricians and Gynecologists (ACOG) recommends that all pregnant women be offered a screening test for Down syndrome, regardless of the woman’s age. Screening may be a maternal blood test done in the first trimester (at 11 to 13 weeks of pregnancy) along with a special ultrasound to measure the thickness at the back of the baby’s neck (called nuchal translucency). Or it can be a maternal blood test done in the second trimester (at 15 to 20 weeks) without the ultrasound. The screening test helps identify pregnancies that are at higher-than-average risk of Down syndrome. However, the screening test cannot diagnose Down syndrome or other birth defects.
With rare exceptions, men with Down syndrome cannot father a child. A woman with Down syndrome has a 50-50 chance of conceiving a child with Down syndrome, but many affected fetuses are miscarried.