Down综合征与正常核型的孪生姐妹细胞遗传学及DNA多态性分析  

Cytogenetic and polymorphic analysis for a trisomy 21 and a normal twin girls.

作　　者：陈亚军[1] 崔英霞[2] 王咏梅[2] 

机构地区：[1]江苏省中医院检验科 [2]南京军区南京总医院检验中心生殖遗传室,江苏南京210002

出　　处：《中国优生与遗传杂志》2005年第2期51-52,58,共3页Chinese Journal of Birth Health & Heredity

摘　　要：目的　报告 1对异卵孪生姊妹 ,分别为 2 1三体综合症患者和表型核型正常的个体 ,并讨论患者额外 2 1号染色体的来源。方法　对孪生姊妹进行外周血淋巴细胞染色体核型分析和 15个DNA微卫星位点多态性分析。结果　孪生姐姐核型为 4 7,XX ,+2 1,孪生妹妹核型为 4 6 ,XX。孪生姊妹 15个STR位点与其父母比较 ,5个位点上显示有来自母亲的不同标志物 ,6个位点上显示有来自父亲的不同标志物。 2 1三体综合征患者在D2 1S11位点上显示有 3个不同的标志物 ,其中 2个源自母亲。结论　孪生姐妹为异卵孪生 ,孪生姐姐额外的 2 1号染色体来自于母亲第 1次减数分裂不分离。Objective: To report a trisomy 21 and a normal twin girls and discuss the origin of the extra chromosome 21 of the patient. Methods: Cytogenetic analysis were carried on lymphocytes from the twin girls. Microsatellite DNA polymorphisms (Short tandem repeats) were detected from the twin girls and their parents. Results: 47,XX,+21 were found from the elder sister and 46,XX from the younger sister. The elder sister differed from younger sister in 5 STR loci originated from the mother and in 6 loci from the father in comparison with those of the parents. Three alleles were found from the patient in locus D21S11 and two from the mother. Conclusion: The twin girls originate from dizygotic and the extra chromosome 21 of the elder sister is from nondisjunction during the first meiotic division of the mother.

关 键 词：DNA微卫星多态性 短串联重复序列 DOWN综合征 双卵挛生 

分 类 号：R725.9[医药卫生—儿科]