What can be done to prevent the condition?

Down syndrome is caused by a chromosome abnormality that is present when conception occurs. So there is no way to prevent Down syndrome in a person who has already been born. Some women may want to have their child screened for Down syndrome during early pregnancy. If screening detects Down syndrome in the child, some women may elect to have an elective abortion. Genetic counseling is also useful for the families of affected children.

What are the long-term effects of the condition?

People with Down syndrome are more at risk for some diseases and conditions, including:

The life span for people with Down syndrome is shorter than average. Congenital heart disease is the leading cause of death in infants with Down syndrome. Otherwise, 3 of 4 people with Down syndrome reach 30 to 35 years of age. Common causes of death in older individuals include lung disease, infections, hepatitis, and leukemia, a cancer of the blood. Chronic infections of the eyes and nose, tooth disease, and thyroid gland problems are common at all ages.

What are the risks to others?

Down syndrome is not contagious. Males with Down syndrome have not been known to have children and females rarely do. Therefore, the disorder usually is not passed from one affected person to another.

Possibly because of genetic reasons, parents who have had one affected child are at slightly higher risk than others to have another affected child. In some cases, the risk may be much higher if the parents have certain genetic problems. For this reason, genetic counseling for families of people with Down syndrome may be helpful.