腓骨肌萎缩症CMTX1型的间隙连接蛋白32基因突变检测

Detection of connexin32 gene mutation in Xlinked dominant Charcot-Marie-Tooth disease

目的检测无基因重复的腓骨肌萎缩症患者间隙连接蛋白32(connexin32,Cx32)基因的突变情况。方法应用变性高效液相色谱(DHPLC)结合混合样品池法和脱氧核糖核酸(DNA)序列测定对1个临床可疑的X连锁显性遗传的腓骨肌萎缩症CMTX1型家系的先证者和15名家庭成员及60名家系外健康对照者进行Cx32基因外显子2的基因编码区突变检测,分3个片段扩增其基因编码区全长。结果先证者在片段2的DHPLC中发现杂合双峰,经DNA序列测定证实其Cx32外显子2发生Leu89Pro(266T→C)错义突变;家系内其他4例发病者和5名未发病者Cx32外显子2都有与先证者一致的DHPLC杂合双峰。60名健康对照者中未发现上述改变。结论Leu89Pro是该家系的致病性突变。该突变体的致病机制如何,有待于做进一步研究。

Objective To detect connexin32 （Cx32） gene mutation in Charcot-Marie-Tooth disease （CMT） patients without CMT1A gene duplication. Methods Mutation analysis of Cx32 gene was performed by denaturing high-performance liquid chromatography （DHPLC） in combining with DNA pooling and DNA sequencing. The proband and 15 family members in a clinical possible X-linked dominant Chareot-Marie-Tooth disease （CMTX1） and 60 normal controls out of the family were studied. Three fragments including the whole ceding region of Cx32 gene were amplified by polymerase chain reaction. Results Heteroduplex chromatogram was detected in fragment II in proband by DHPLC and Leu89Pro （266T→C ）missense mutation in exon 2 of Cx32 gene was proved by DNA sequencing. The same double peaks were detected in 4 patients and 5 carriers, but not detected in normal controls. Conclusions Leu89Pro should be the pathogenic mutation in this family. Further study is needed to investigate the pathogenesis of the mutant.