downs syndrome

Down's syndrome

A congenital condition, caused by an abnormality in the chromosomes, marked by moderate to severe mental retardation and changes in certain physical features.

Down''s Syndrome 

Main Entry: Down syndrome
Variant: or Down's syndrome /'daun(z)-/
Function: noun
: a congenital condition characterized by moderate tosevere mental retardation, slanting eyes, a broad short skull, broad hands with short fingers, and by trisomy of the human chromosome numbered 21 called also Down's, trisomy 21
Down /'daun/, John Langdon Haydon (1828–1896), British physician. Down published in 1866 a treatise on the degeneration of race as a result of marriages ofconsanguinity. He classified individuals exhibiting mental retardation according to the supposed physiognomic features of various races including the American Indian, Caucasian, Ethiopian, andMongolian. Although his classification is invalid, one kind of moderate to severe mental retardation was known until recently as mongolism and is now called Down syndrome or Down's syndrome.

Down syndrome (doun) or Down's syndrome (dounz)
n.
A congenital disorder, caused by the presence of an extra 21st chromosome, in which the affected person has mild to moderate mental retardation, short stature, and a flattened facial profile. Also called trisomy 21, trisomy 21 syndrome.

Down syndrome (doun) or Down's Syndrome   (doun)  Pronunciation Key  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).