Fetni R, Krabchi K, Messier P E, Richer C L, Lemieux N
Département de Pathologie, Faculté de Médecine, Université de Montréal, Québec, Canada.
Am J Med Genet. 1996 Jun 14;63(3):454-7. doi: 10.1002/(SICI)1096-8628(19960614)63:3<454::AID-AJMG7>3.0.CO;2-R.
A patient with mixed gonadal dysgenesis and Y isochromosomes i(Y) is described. Lymphocyte cultures from peripheral blood contained a high proportion of 45,X cells and several other cell lines with two different marker chromosomes (mars). These markers had either a monocentric (mar1) or a dicentric appearance (mar2). Following high-resolution GTG, RBG, QFQ, and CBG bandings, five cell lines were identified; 45,X/46,X,+mar1/46,X,+mar2/47,X,+mar1x2/47,X,+mar2x 2. The percentages were 66/6/26/1/1%, respectively. Chromosome banding analyses were insufficient for characterization of the markers. In situ hybridization of specific probes for the Y centromere and its short arm showed, both in fluorescence and electron microscopy (EM), two different Y rearrangements. Mar1 is an isochromosome for the short arm i(Yp) and mar2 is a dicentric which was shown by EM to be a double isochromosome Yp, inv dup i(Yp). The breakpoint producing mar1 is within the centromere and the one producing mar2 is within one of the short arms of the Y isochromosome. The findings of different cell populations in peripheral blood lymphocytes indicate the postzygotic instability of this i(Yp).
本文描述了一名患有混合性性腺发育不全和Y等臂染色体i(Y)的患者。外周血淋巴细胞培养物中含有高比例的45,X细胞以及其他几种带有两条不同标记染色体（mar）的细胞系。这些标记染色体呈现单着丝粒（mar1）或双着丝粒外观（mar2）。经过高分辨率GTG、RBG、QFQ和CBG显带分析，鉴定出五个细胞系；45,X/46,X,+mar1/46,X,+mar2/47,X,+mar1x2/47,X,+mar2x 2。其比例分别为66/6/26/1/1%。染色体显带分析不足以对这些标记染色体进行特征描述。针对Y着丝粒及其短臂的特异性探针原位杂交显示，无论是在荧光显微镜还是电子显微镜（EM）下，都存在两种不同的Y染色体重排。Mar1是短臂等臂染色体i(Yp)，mar2是双着丝粒染色体，电子显微镜显示其为双等臂染色体Yp，倒位重复i(Yp)。外周血淋巴细胞中不同细胞群体的发现表明这种i(Yp)在合子后具有不稳定性。
