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Down syndrome

noun

Simple Definition of Down syndrome

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

Source: Merriam-Webster's Learner's Dictionary

Full Definition of Down syndrome

  1. :  a congenital condition characterized by moderate to severe mental retardation, slanting eyes, a broad short skull, broad hands with short fingers, and trisomy of the human chromosome numbered 21 —called also Down's syndrome

Origin of down syndrome

J. L. H. Down †1896 English physician


First Known Use: 1961


Medical Dictionary

Down syndrome

noun

Medical Definition of Down syndrome

  1. :  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 \ˈdau̇n\play , 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.

Variants of down syndrome

or Down's syndrome

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