青少年型亨廷顿病一家系临床特征及遗传学特点分析

Clinical and genetic analyses of one juvenile-onset Huntington disease family

目的探讨青少年型亨廷顿病的临床特征及遗传学特点。方法对郑州大学第五附属医院神经内科2015年2月收治的一临床拟诊为青少年型亨廷顿病家系成员的临床资料进行收集，绘制遗传系谱图。同时按照知情和自愿参与原则，对该家系7人基因，运用片段分析方法对，IT15基因进行检测。结果该家系遗传系谱图符合常染色体显性遗传。该家系共3人发病，2人已死亡，其中2人为青少年期发病，临床表现以肌张力障碍、构音障碍、共济失调及认知功能障碍为主；该家系进行IT15基因检测的7人中，4人正常，3人胞嘧啶-腺嘌呤-鸟嘌呤三核苷酸（CAG）重复序列异常扩增，CAG重复次数分别为59次、60次、57次。结论（1）青少年型亨廷顿病的临床特征以肌张力障碍为突出表现，伴有构音障碍、共济失调及认知功能障碍，病程进展较快；（2）该家系患者发病有遗传早现现象。

Objective To investigate the clinical and genetic features of juvenile-onset Huntington disease （HD）. Methods The clinical data of members from one juvenile-onset HD family, admitted to our hospital in February 2015, were collected, and the family pedigree tree was drawn. Peripheral venous blood of volunteers of this family was extracted to pursue IT15 genetic test. Results The pedigree tree indicated that HD was autosomal dominant inheritance. There were 3 patients in this family, 2 of them died, and 2 were juvenile-onset HD. Clinical manifestations of these patients were characterized by dystonia, dysarthria, ataxia and cognitive dysfunction. Among 7 participants who pursued genetic test, 4 were normal, and 3 carried expanded alleles, whose cytosine - adenine - guanine trinucleotide （CAG） repeat number was 59, 60, and 57, respectively. Conclusions （1） The clinical manifestations of juvenile-onset HD are characterized by dystonia, dysarthria, ataxia and cognitive dysfunction; juvenile-onset HD has rapid progression. （2） The phenomenon called ＂anticipation＂ is found in this family.