1) Backwardness 2) Birth defect 3) Congenital abnormality 4) Congenital anomaly 5) Congenital defect 6) Congenital disorder 7) Down syndrome 8) Mental retardation 9) Mongolism 10) Retardation 11) Slowness 12) Subnormality 13) Trisomy 14) Trisomy 21 1) Mongolism