Skip to main content
An official website of the United States government
Español
Government Funding Lapse
Because of a lapse in government funding, the information on this website may not be up to date, transactions submitted via the website may not be processed, and the agency may not be able to respond to inquiries until appropriations are enacted.

The NIH Clinical Center (the research hospital of NIH) is open. For more details about its operating status, please visit cc.nih.gov.

Updates regarding government operating status and resumption of normal operations can be found at opm.gov.

trisomy 18

(TRY-soh-mee …)
A genetic disorder caused by having an extra chromosome 18 in some or all of the body’s cells. Trisomy 18 is marked by a low birth weight and certain abnormal features. These include a small, abnormally shaped head; a small jaw and mouth; clenched fists with overlapping fingers; and heart, lung, kidney, intestine, and stomach defects. Many babies with trisomy 18 die before birth or within the first month of life, but some children live for several years. Having trisomy 18 increases the risk of certain types of cancer, such as hepatoblastoma (a type of liver cancer) and Wilms tumor (a type of kidney cancer). Also called Edwards syndrome.
More Information
Search NCI's Dictionary of Cancer Terms