一个发作性运动诱发性肌张力障碍家系的PRRT2基因突变研究

Analysis of PRRT2 gene mutations in a Chinese family affected with paroxysmal kinesigenic dyskinesia

目的确定一个中国汉族发作性运动诱发性肌张力障碍（paroxysmal kinesigenic dyskinesia，PKD）家系中富脯氨酸跨膜蛋白2（proline—richtransmembrane protein，PRRT2）基因的突变情况。方法收集该家系患者及正常者的外周血，PCR扩增PRRT2基因的外显子及外显子与内含子连接区，PCR产物直接正反向测序并与数据库进行比对，确定有无PRRT2基因突变以及突变的位点。结果在该家系患者中均检测出了PRR222基因C．649dupC的移码突变。该突变可导致终止密码子的提前形成，使PRRT2蛋白发生截短，经查阅人类基因突变数据库证实该突变与PKD相关。家系中表型正常人未检测到该突变。结论PRRT2基因c．649dupC移码突变可能是该发作性运动诱发性肌张力障碍家系的致病原因，通过基因诊断和产前诊断可以有效阻止致病基因的侍谱。降低生育患儿的风险。

Objective To screen potential mutations of PRRT2 gene in a Chinese family affected with paroxysmal kinesigenic dyskinesia （PKD）. Methods Polymerase chain reaction, DNA sequencing and restriction endonuclaese analysis were used to analyze all members of the family. Results A heterozygous mutation c. 649dupC was identified in the PRRT2 gene in all patients, while no similar mutation was found in healthy members from the family. Conclusion The c. 649dupC mutation of the PRRT2 gene probably underlies the PKD in this family. Prenatal diagnosis can reduce the risk for further birth of affected children for this family.