Raeymaekers P, Timmerman V, Nelis E, Van Hul W, De Jonghe P, Martin J J, Van Broeckhoven C
Laboratory of Neurogenetics, Born-Bunge Foundation, Department of Biochemistry, University of Antwerp (UIA), Belgium.
J Med Genet. 1992 Jan;29(1):5-11. doi: 10.1136/jmg.29.1.5.
We have previously shown a duplication in 17p11.2 with probe pVAW409R3 (D17S122) in 12 families with hereditary motor and sensory neuropathy type I (HMSN I) or Charcot-Marie-Tooth disease type 1 (CMT1). In this study we aimed to estimate the size of the duplication using additional polymorphic DNA markers located in 17p11.2-p12. Two other 17p11.2 markers, pVAW412R3 (D17S125) and pEW401 (D17S61), were found to be duplicated in all HMSN I patients tested. Furthermore, all HMSN I patients showed the same duplication junction fragment with probe pVAW409R3. On the genetic map the duplicated markers span a minimal distance of 10 cM while on the physical map they are present in the same NotI restriction fragment of 1150 kb. The discrepancy between the genetic and physical map distances suggests that the 17p11.2 region is extremely prone to recombinational events. The high recombination rate may be a contributing factor to the genetic instability of this chromosomal region.
我们先前已在12个患有遗传性运动感觉神经病I型（HMSN I）或1型夏科-马里-图斯病（CMT1）的家族中发现，17p11.2区域存在用探针pVAW409R3（D17S122）检测到的重复片段。在本研究中，我们旨在使用位于17p11.2 - p12区域的其他多态性DNA标记来估计该重复片段的大小。结果发现，另外两个17p11.2标记，即pVAW412R3（D17S125）和pEW401（D17S61），在所有接受检测的HMSN I患者中均表现为重复。此外，所有HMSN I患者与探针pVAW409R3均显示相同的重复连接片段。在遗传图谱上，这些重复的标记跨度最小为10厘摩（cM），而在物理图谱上，它们存在于一个1150 kb的相同NotI限制酶切片段中。遗传图谱距离与物理图谱距离之间的差异表明，17p11.2区域极易发生重组事件。高重组率可能是导致该染色体区域遗传不稳定的一个因素。
