劍橋詞典a condition in which someone has three rather than two chromosomes in some or all of the body cells 三體綜合癥 Trisomy 21 syndrome , also called Down's syndrome , affects physical and mental development . 21-三體綜合征，又稱唐氏綜合癥，影響身體和精神的發(fā)育。 返回 trisomy syndrome