n. 先天愚型

[医] 先天愚型, 伸舌样白痴

[ noun ]
a congenital disorder caused by having an extra 21st chromosome; results in a flat face and short stature and mental retardation
<noun.state>

Down syndrome \Down" syn`drome\, Down's syndrome \Down's"
syn`drome\, n. (Med.)
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}.
[PJC]