Down or Down's, Syndrome
   Down's syndrome, or Down syndrome, is a disorder caused by chromosome abnormalities that develop during germ-cell formation. If the affected ovum or sperm takes part in fertilization, the fetus will exhibit the syndrome. Characteristics include moderate to severe mental deficiency, slow physical development, stocky build, short hands, and flattened facial features.
   The syndrome was first described in 1866 by Dr. John Langdon Haydon Down (1828-1896), born in London and for many years a fellow of the Royal College of Physicians. The disorder had been called mongolism because of the Asian characteristics of eyes that appear to slant, but Down's name was later given to this disorder. In 1959 a French biologist, Jerome Lejeune, established that the production of a germ cell with an extra chromosome 21 is the most common cause of Down's syndrome.
   The possibility of this happening is more likely in the firstborn of an older mother, over forty years of age. Chromosome 21 is the smallest human chromosome, but its genes are of great importance not only in Down's syndrome but in cancer and Alzheimer's disease. People suffering from Down's syndrome may, with recent developments in medicine, live to about fifty years of age, but such individuals do not ordinarily become self-supporting. They are, nevertheless, often unusually sociable and affectionate.

Dictionary of eponyms. . 2013.

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  • Syndrome de west — Le syndrome de West, aussi connu sous le nom de spasmes infantiles, est une forme rare d épilepsie du nourrisson. Nommé d après le docteur anglais, William James West (1793 1848), qui le premier en a fait la description dans un article publié… …   Wikipédia en Français

  • Down syndrome — Down′ or Down s syndrome n. pat a genetic disorder associated with the presence of an extra chromosome 21, characterized by mental retardation, weak muscle tone, and epicanthic folds at the eyelids Formerly, mongolism Also called trisomy 21… …   From formal English to slang

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  • Syndrome de West — Le syndrome de West, aussi connu sous le nom de spasmes infantiles, est une forme rare d épilepsie du nourrisson. Nommé d après le médecin anglais William James West (1793 1848), qui le premier en a fait la description dans un article publié dans …   Wikipédia en Français

  • Down syndrome — noun a congenital disorder caused by having an extra 21st chromosome; results in a flat face and short stature and mental retardation • Syn: ↑mongolism, ↑mongolianism, ↑Down s syndrome, ↑trisomy 21 • Hypernyms: ↑trisomy, ↑birth defect, ↑ …   Useful english dictionary

  • down — down1 /down/, adv. 1. from higher to lower; in descending direction or order; toward, into, or in a lower position: to come down the ladder. 2. on or to the ground, floor, or bottom: He fell down. 3. to or in a sitting or lying position. 4. to or …   Universalium

  • Syndrome de down — « trisomie 21 » redirige ici. Pour les autres significations, voir Trisomie 21 (groupe) …   Wikipédia en Français

  • Down Syndrome Centre — is a registered Irish charity that was set up in 2002 by parents of children with Down syndrome. The aim of the charity is to establish Ireland’s first centre to provide a range of dedicated services medical, developmental and educational which… …   Wikipedia

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  • Down's syndrome — Down syndrome a condition resulting from a chromosomal abnormality most commonly due to the presence of three copies of chromosome 21 (trisomy 21), which is most likely to occur with advanced maternal age. Down s syndrome can also occur as a… …   The new mediacal dictionary

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