Leal-Garza C H, Cortés-Gutiérrez E I, Ortiz-Jalomo R, García-Cavazos R
Centro de Investigación Biomédica del Noreste, Instituto Mexicano del Seguro Social, Monterrey N.L. México.
Rev Invest Clin. 1996 Sep-Oct;48(5):385-8.
A baby with stigmata of Down's syndrome was found to be a mosaic with two different cell lines: 45,XX,der(14q;21q)/46,XX,der(21q;21q)+21. The chromosome rearrangements appeared to have risen de novo. Four mechanisms are discussed for the origin of the mosaicism: dissociation of a translocation (14q;21q) chromosome already present in the 45,XX, der(14q;21q) zygote; two translocation events occurring sequentially at the first and second zygote (46,XX) divisions; a chromatid translocation in a 47,XX,+21 zygote; and an independent origin of the two cell lines.
45,XX,der(14q;21q)/46,XX,der(21q;21q)+21。染色体重排似乎是新生的。文中讨论了嵌合体形成的四种机制：45,XX, der(14q;21q)合子中已存在的易位(14q;21q)染色体的解离；在合子(46,XX)的第一次和第二次分裂时依次发生的两次易位事件；47,XX,+21合子中的染色单体易位；以及两种细胞系的独立起源。
