SymptomsBy Mayo Clinic staff
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
Children with Down syndrome may also have:
- Poor muscle tone
- Broad, short hands with a single crease in the palm
- Relatively short fingers
- Excessive flexibility
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.
- Facts about Down syndrome. National Institute of Child Health and Human Development. http://www.nichd.nih.gov/publications/pubs/downsyndrome.cfm. Accessed Feb. 14, 2011.
- Barss V, et al. Overview of prenatal screening and diagnosis of Down syndrome. http://www.uptodate.com/home/index.html. Accessed Feb. 14, 2011.
- Esbensen AJ. Health conditions associated with aging and end of life of adults with Down syndrome. International Review of Research in Mental Retardation. 2010;39:107.
- What causes Down syndrome? National Down Syndrome Society. http://www.ndss.org/index.php?option=com_content&task=category§ionid=23&id=60&Itemid=234. Accessed Feb. 14, 2011.
- Genetic conditions: Down syndrome. Genetics Home Reference. http://ghr.nlm.nih.gov/condition=downsyndrome. Accessed Feb. 14, 2011.
- ACOG practice bulletin no. 77: Screening for fetal chromosomal abnormalities. Obstetrics and Gynecology. 2007;109:217.
- Birth defects: Down syndrome. Centers for Disease Control and Prevention. http://www.cdc.gov/ncbddd/birthdefects/DownSyndrome.htm. Accessed Feb. 15, 2011.
- Roizen NJ. Clinical features and diagnosis of Down syndrome. http://www.uptodate.com/home/index.html. Accessed Feb. 15, 2011.
- Birth defects. In: American College of Obstetricians and Gynecologists. Your Pregnancy and Childbirth Month to Month. 5th ed. Washington, D.C.: American College of Obstetricians and Gynecologists; 2010:343.
- Harms RW (expert opinion). Mayo Clinic, Rochester, Minn. Feb. 15, 2011.
- Chiu RWK, et al. Non-invasive prenatal assessment of trisomy 21 by multiplexed maternal plasma DNA sequencing: Large scale validity study. British Medical Journal. 2011;342:7401.