Down syndrome is a common genetic disorder. Down syndrome causes birth defects, medical problems, and some degree of intellectual disability.
Chromosomes contain the genetic makeup of your body. They occur in 23 pairs within the body. Down syndrome is a problem with chromosome pair 21. There is extra genetic material on the chromosome that may be caused by:
Factors that increase the chance for Down syndrome include:
Infants born with Down syndrome may have some or all of the following physical features:
The degree of medical problems and intellectual disability is different for each person. Talents, abilities, and pace of development will be different, too. People with Down syndrome may be born with or develop:
Most of these health problems are treatable. The majority of people born with Down syndrome have a life expectancy of about 55 years.
Doctors can usually identify a child born with Down syndrome at birth. When Down syndrome is suspected, a blood test will be done to confirm it.
Down syndrome may also be diagnosed before birth. There are screening tests and diagnostic tests to help identify chormosome abnormalities before birth.
A screening test is done to estimate the risk of having a child with Down syndrome. Your doctor will use the results of a variety of blood tests and the mother's age to estimate the risk. Blood tests may include:
Screening may be done as early as 11 weeks. It may also include both ultrasound imaging and blood screening. There should be a follow-up in the second trimester for those who have a negative screening.
A small amount of women who have screening will be given false-positive readings. This means the test indicates Down syndrome even when it does not exist.
Diagnostic tests will tell if the fetus actually has Down syndrome. These tests include:
These tests are about 98%-99% accurate. Each test requires that a small piece of tissue be removed from the placenta or umbilical cord. This creates a small risk of miscarriage with these tests.
There is no cure for Down syndrome.
Some newborns may need surgery to repair serious medical problems, like heart defects.
Treatment may be needed for severe problems or to help with developmental delays. Living at home and receiving special therapy helps children with Down syndrome achieve their full potential. Most people with the condition can actively participate in the community. This includes activities at schools, jobs, and various leisure activities. Some people with Down syndrome live with family, some live with friends, and some live independently.
Infants with Down syndrome may take longer to feed. A child with Down syndrome will also start talking, playing, and performing other activities later than normal.
Learning opportunities may be increased with:
Speech, physical, and occupational therapy may improve abilities. Therapy can help with speech, walking, and performing activities of daily living.
National Down Syndrome Congress
National Down Syndrome Society
Canadian Down Syndrome Society
Benn P, et al. Prenatal detection of Down syndrome using massively parallel sequencing (MPS): A rapid response statement from a committee on behalf of the Board of the International Society for Prenatal Diagnosis, 24 October 2011. Prenat Diagn. 2012;32:1-2.
Committee opinion No. 545: Noninvasive prenatal testing for fetal aneuploidy. Obstet Gynecol. 2012;120(6):1532-1534.
Down syndrome. EBSCO DynaMed Plus website. Available at: http://www.dynamed.com/topics/dmp~AN~T115414/Down-syndrome. Updated March 3, 2016. Accessed September 29, 2016.
Down Syndrome. National Institute of Child Health and Human Development website. Available at: http://www.nichd.nih.gov/health/topics/down/Pages/default.aspx. Updated April 3, 2013. Accessed May 21, 2013.
Malone FD, Canick JA, et al. First- and second-trimester evaluation of risk (FASTER) research consortium. First-trimester or second-trimester screening, or both, for Down's syndrome. N Engl J Med. 2005;353:2001-2011.
What is Down syndrome? National Down Syndrome Society website. Available at: http://www.ndss.org/Down-Syndrome/What-Is-Down-Syndrome. Accessed May 21, 2013.
3/12/2010 DynaMed Plus Systematic Literature Surveillance http://www.dynamed.com/topics/dmp~AN~T115414/Down-syndrome: Carter M, McCaughey E, et al. Sleep problems in a Down syndrome population. Arch Dis Child. 2009;94(4):308-310.
Last reviewed January 2015 by Rimas Lukas, MD
Please be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding a medical condition.