Down syndrome due to de novo Robertsonian translocation t(14q;21q): DNA polymorphism analysis suggests that the origin of the extra 21q is maternal.
Down syndrome due to de novo Robertsonian translocation t(14q;21q): DNA polymorphism analysis suggests that the origin of the extra 21q is maternal.
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DOI：
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发表时间：
1991-09
影响因子：
9.8
通讯作者：
M. Petersen;P. A. Adelsberger;A. Schinzel;F. Binkert;G. Hinkel;S. Antonarakis
中科院分区：
文献类型：
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作者：
M. Petersen;P. A. Adelsberger;A. Schinzel;F. Binkert;G. Hinkel;S. Antonarakis
唐氏综合征很少是由于从头罗伯逊易位t（14 q; 21 q）。8个先天性唐氏综合征家系的DNA多态性均显示额外染色体21 q的母系起源。在7个非嵌合体的情况下，DNA标记显示两个母亲染色体21之间的交叉，在一个嵌合体的情况下，没有观察到交叉（这种情况下可能是由于早期的合子后不分离）。在大多数情况下（五个六个信息的家庭）的近端标记D21 S120减少到纯合性的后代与三体21。这些数据可以用减数分裂I中的染色单体易位以及减数分裂I和减数分裂II中的正常交换和分离来最好地解释。
Down syndrome is rarely due to a de novo Robertsonian translocation t(14q;21q). DNA polymorphisms in eight families with Down syndrome due to de novo t(14q;21q) demonstrated maternal origin of the extra chromosome 21q in all cases. In seven nonmosaic cases the DNA markers showed crossing-over between two maternal chromosomes 21, and in one mosaic case no crossing-over was observed (this case was probably due to an early postzygotic nondisjunction). In the majority of cases (five of six informative families) the proximal marker D21S120 was reduced to homozygosity in the offspring with trisomy 21. The data can be best explained by chromatid translocation in meiosis I and by normal crossover and segregation in meiosis I and meiosis II.