多巴反应性肌张力障碍GCH1基因突变分析

目的探讨多巴反应性肌张力障碍（dopa responsive dystonia,DRD）三磷酸鸟苷环化水解酶Ⅰ基因（guanosinetriphosphate cyclohydrolaseⅠ,GCH1）的突变。方法应用聚合酶链反应、DNA直接测序和限制性内切酶酶切技术对6例散发DRD患者进行GCH1基因的突变分析,对100名健康对照者进行GCH1基因的PCR和限制性内切酶酶切分析。结果1例患者检测出GCH1基因一个新的点突变151（G→A）,为起始密码子突变,导致所编码的起始氨基酸由蛋氨酸变为异亮氨酸（M1I）而不能起始翻译。100名健康对照者等位基因无此突变。结论发现了GCH1基因一个新的杂合型点突变151（G→A）,我国散发DRD患者中存在GCH1基因突变。

Mutation analysis of GCH1 gene in Chinese patients with dopa responsive dystonia

OBJECTIVE: To detect mutations of guanosine triphosphate cyclohydrolase I (GCH1) gene in Chinese patients with dopa responsive dystonia (DRD). METHODS: Six sporadic patients with DRD were examined. GCH1 gene mutations were detected using polymerase chain reaction (PCR), DNA sequence analysis and restriction enzyme digestion analysis. One hundred normal people were detected using PCR and restriction enzyme digestion analysis. RESULTS: A new point mutation, 151(G-->A) in exon one was found in a patient. It lead to substitution of a methionine for isoleucine at amino acid 1(M1I). This mutation was not found in normal control people. CONCLUSION: The authors report a new heterozygotic point mutation 151(G-->A) in GCH1 gene. There are GCH1 gene mutations in Chinese sporadic patients with DRD.