01 n. A congenital disorder caused by an extra chromosome 21 in some or all cells. It causes a variable number and degree of abnormalities, incl…
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A congenital disorder caused by an extra chromosome 21 in some or all cells. It causes a variable number and degree of abnormalities, including retarded growth, mental retardation, a short nose, prominent epicanthic folds on the eyelids, a protruding lower lip, and other physical features having varying degrees of deviation from the normal. Called also mongolism, trisomy-21 and trisomy 21 syndrome.(Med.) Also: mongolism, trisomy-21, trisomy 21 syndrome