Down syndrome

noun

variants: or Down's syndrome

Definition of Down syndrome

: a congenital condition characterized especially by developmental delays, usually mild to moderate impairment in cognitive functioning, short stature, upward slanting eyes, a flattened nasal bridge, broad hands with short fingers, decreased muscle tone, and by trisomy of the human chromosome numbered 21 — called also trisomy 21

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Origin and Etymology of down syndrome

J. L. H. Down †1896 English physician

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First Known Use: 1961

in the meaning defined above

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DOWN SYNDROME Defined for English Language Learners

Down syndrome

noun

Definition of Down syndrome for English Language Learners

medical : a condition that someone is born with and that causes below average mental abilities and problems in physical development

Medical Dictionary

Down syndrome

noun

variants: or Down's syndrome

medical Definition of Down syndrome

: a congenital condition characterized especially by mental retardation, short stature, relatively small head, upward slanting eyes usually with epicanthal folds, flattened nasal bridge, broad hands with short fingers, decreased muscle tone, and by trisomy of the human chromosome numbered 21 — called also Down, Down's, trisomy 21

Biographical Note for down syndrome

Down play \ˈdau̇n\, John Langdon Haydon (1828–1896), British physician. Down published in 1866 a treatise on the degeneration of race as a result of marriages of consanguinity. He classified individuals exhibiting mental retardation according to the supposed physiognomic features of various races including the American Indian, Caucasian, Ethiopian, and Mongolian. His classification was invalid, but one kind of moderate to severe mental retardation came to be known as mongolism, although it is now called Down syndrome or Down's syndrome.