trisomy 21

Noun trisomy 21 has 1 sense

• trisomy 21(n = noun.state) down syndrome, down's syndrome, mongolianism, mongolism - a congenital disorder caused by having an extra 21st chromosome; results in a flat face and short stature and mental retardation;
is a kind of birth defect, congenital abnormality, congenital anomaly, congenital defect, congenital disorder, trisomy