遗传性多巴反应性肌张力障碍一家系

Hereditary dopa-responsive dystonia： report of a family

目的 探讨一个遗传性多巴反应性肌张力障碍（dopa-responsive dystonia,DRD）家系的临床特点及相关基因突变.方法 收集一个DRD家系的临床资料及外周血样本,提取全基因组DNA,应用聚合酶链反应（PCR）及DNA直接测序方法进行三磷酸鸟苷环化酶-1（GCH-1）基因外显子突变检测.结果 该家系患病成员临床特点方面个体差异较大,但所有患者均对左旋多巴制剂反应良好,且未见明显不良反应.基因分析显示5例患者及1例无症状直系亲属存在GCH-1基因第6号外显子上的缺失突变c.63 1_632delAT,引起框移突变.结论 DRD临床表现具有明显异质性,在同一家系不同患者之间存在较大差异,同一基因突变可引起不同的临床表现型,部分携带者可不发病.GCH-1基因第6号外显子上的缺失突变c.631_632delAT为DRD致病的遗传学基础之一.

Objective To evaluate the clinical features and guanosine triphosphate cyclohydrolase 1 （GCH-1） gene mutation in a family with dopa-responsive dystonia （DRD）.Methods The clinical features of this family were collected and their peripheral blood samples were screened for mutation in GCH-1 gene using PCR and DNA direct sequencing.Results The clinical features among each patient in this family were different.But all affected family members had quite a good response to levodopa treatment without significant adverse reactions.DNA test showed an AT deletion mutation at point of 631-632 in the 6th exon of GCH-1 gene in 5 affected members and 1 asymptomatic immediate family member.Conclusions Clinical heterogeneity is an important characteristic of DRD and clinical symptoms vary intra-families.Same gene type may cause different phenotype and not all carriers are patients.The deletion mutation at point of 631-632 in the 6th exon of GCH-1 gene should be considered as a pathogenic mutation for DRD.