Down syndrome
or Down's syndrome
nounPathology.
a genetic disorder, associated with the presence of an extra chromosome 21, characterized by mild to severe mental impairment, weak muscle tone, shorter stature, and a flattened facial profile.
Origin of Down syndrome
1First recorded in 1960–65; after John L. H. Down (1828–96), British physician
- Also called trisomy 21 .
usage note For Down syndrome
Down syndrome (or Down's syndrome ) has replaced earlier terms, such as mongolism to refer to the disease and Mongoloid or Mongol to refer to the affected person, all of which are now considered offensive.
- See also trisomy.
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2024
Scientific definitions for Down syndrome
Down syndrome
[ doun ]
A congenital disorder caused by the presence of an extra 21st chromosome. People with Down syndrome have mild to moderate mental retardation, short stature, and a flattened facial profile. The syndrome is named after its discoverer, British physician John Langdon Haydon Down (1828-1896).
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
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