Szabo P, Purrello M, Rocchi M, Archidiacono N, Alhadeff B, Filippi G, Toniolo D, Martini G, Luzzatto L, Siniscalco M
Proc Natl Acad Sci U S A. 1984 Dec;81(24):7855-9. doi: 10.1073/pnas.81.24.7855.
The human gene for glucose-6-phosphate dehydrogenase (G6PD) has been subregionally mapped to band Xq28 by segregation analysis in rodent-human somatic cell hybrids [Pai, G. S., Sprinkel, J. A., Do, T. T., Mareni, C. E. & Migeon, B. R. (1980) Proc. Natl. Acad. Sci. USA 77, 2810-2813]. We have previously reported a common type of X-linked mental retardation associated with an inducible fragile site at Xq27-Xq28 segregates in a close linkage relationship with a G6PD variant, but the relative position of G6PD with respect to the fragile site has not yet been established. This fragile-X syndrome has been shown to be closely linked also to a Taq I restriction fragment length polymorphism detected by a cDNA probe for factor IX, and the latter locus has been mapped to the subtelomeric region Xq26-Xq28 [Camerino, G., Mattei, M. G., Mattei, G. F., Jaye, B. & Mandel, J. L. (1983) Nature (London) 306, 701-704]. The in situ hybridization studies reported here provide strong evidence that G6PD is located on the Xq telomeric fragment distal to the fragile site. These observations and the well-established knowledge that the genes for Deutan and Protan colorblindness are closely linked to G6PD, but segregate independently of factor IX deficiency, suggest that the fragile site associated with this type of X-linked mental retardation occurs in a region prone to high frequency of meiotic recombination.
通过在啮齿动物 - 人类体细胞杂种中的分离分析，已将人类葡萄糖 - 6 - 磷酸脱氢酶（G6PD）基因亚区域定位到Xq28带[Pai, G. S., Sprinkel, J. A., Do, T. T., Mareni, C. E. & Migeon, B. R. (1980) Proc. Natl. Acad. Sci. USA 77, 2810 - 2813]。我们先前报道了一种常见的X连锁智力迟钝类型，它与Xq27 - Xq28处的一个可诱导脆性位点相关，该脆性位点与一种G6PD变体以紧密连锁关系分离，但G6PD相对于脆性位点的相对位置尚未确定。已表明这种脆性X综合征也与用因子IX的cDNA探针检测到的Taq I限制性片段长度多态性紧密连锁，并且后一个位点已定位到亚端粒区域Xq26 - Xq28 [Camerino, G., Mattei, M. G., Mattei, G. F., Jaye, B. & Mandel, J. L. (1983) Nature (London) 306, 701 - 704]。此处报道的原位杂交研究提供了有力证据，表明G6PD位于脆性位点远端的Xq端粒片段上。这些观察结果以及已确立的知识，即红绿色盲的Deutan和Protan基因与G6PD紧密连锁，但与因子IX缺乏独立分离，表明与这种类型的X连锁智力迟钝相关的脆性位点发生在减数分裂重组频率较高的区域。
