Burns J L, Hall J G, Powers E, Callis J B, Hoehn H
Clin Genet. 1979 Jan;15(1):22-8. doi: 10.1111/j.1399-0004.1979.tb02025.x.
Why the frequency of spontaneous abortions among monosomy X conceptuses is 98% while the postnatal course of Turner syndrome is relatively benign has not been understood. One explanation could be that mosaicism for a euploid cell line confers viability and that those 2% of 45,XO zygotes surviving in utero have some degree of mosaicism. We thus reasoned that if the non-mosaic 45,XO karyotype is lethal, a thorough study of living Turner syndrome patients might reveal a much higher frequency of mosaicism than the 30--40% reported. Ten adult women with a 45,XO leukocyte karyotype were investigated, looking at five tissue types from all three germ layers: buccal mucosa and hair from ectoderm, urinary epithelium from endoderm and ectoderm, and lymphocytes and skin fibroblasts from mesoderm. We were unable to confirm mosaicism in these patients, although in 2 out of 10 there was the suggestion of a small percentage of euploid cells in skin and blood karyotypes.
为什么X单体型胚胎的自然流产率为98%，而特纳综合征的产后病程相对良性，这一点尚未明确。一种解释可能是，整倍体细胞系的嵌合现象赋予了生存能力，那些在子宫内存活的45,XO合子中有2%具有一定程度的嵌合现象。因此我们推断，如果非嵌合型45,XO核型是致死性的，那么对存活的特纳综合征患者进行深入研究可能会发现，嵌合现象的发生率比报道的30%-40%要高得多。我们对10名白细胞核型为45,XO的成年女性进行了研究，观察了来自所有三个胚层的五种组织类型：外胚层的颊黏膜和毛发、内胚层和外胚层的尿路上皮，以及中胚层的淋巴细胞和皮肤成纤维细胞。我们无法在这些患者中证实嵌合现象，尽管在10例中有2例在皮肤和血液核型中显示有少量整倍体细胞。
