Down syndrome
nounUK /daʊn ˈsɪndɹəʊm/ · US /daʊn ˈsɪndɹoʊm/
Etymology Named after English physician John Langdon Haydon Down (1828–1896), who first described the condition as a distinct form of mental disability in the 1860s.
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Medicine, Neurology, Neuroscience, Sciences Australia, Canada, Ireland, New Zealand, US, Usually A genetic disorder caused by the presence of all or part of a third copy of chromosome 21 (a chromosomal excess), whereby the patients typically have a delay in cognitive ability and physical growth, as well as a small head and tilted eyelids.
Medical genetics
- Derived terms
- Down syndrome regression disorder