Objective: a few trisomy 21 cells in normal chromosome karyotype was been observed for study of the correlation of clinical phenotype and development damage in sick children of Down's syndrome.
目的观察正常细胞核型中含有极少量21 -三体细胞的患儿临床表型及发育损害的相关关系。
Down syndrome (trisomy 21) is a disorder caused by the presence of an extra 21st chromosome.
唐氏综合症（21三体综合症）是由于患者额外多了一条21号染色体所致的疾病。
Down syndrome (trisomy 21) is a disorder caused by the presence of an extra 21st chromosome.
唐氏综合症（21三体综合症）是由于患者额外多了一条21号染色体所致的疾病。
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