trisomy 21

同根派生

Around 30% of these cases are associated with trisomy 21.
大约30%25这些病例同时合并又21三染色体。
Cases of trisomy 21 were identified from the cytogenetics laboratory logbook.
Down综合征（21三体综合症）的鉴别参照细胞遗传学手册。
Amniocentesis was performed to rule out trisomy 21;the karyotype was normal: 46,XX.
羊水穿刺排除了21三体，染色体组型正常，46，XX。
A short femur is associated with trisomy 21 rather than trisomy 13 and holoprosencephaly.
股骨短与21-三体而不是13-三体或全前脑畸形有关。
Down syndrome (trisomy 21) is a disorder caused by the presence of an extra 21st chromosome.
唐氏综合症（三染色体21）是由于存在额外的第21号染色体而产生的一种疾病。