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目的报告1例齿状核红核苍白球路易体萎缩(DRPLA)患者的临床特征和基因突变特点。方法采用聚合酶链反应对388例脊髓小脑共济失调患者(234例常染色体显性遗传家系先证者和1 54例散发病例)进行初步筛查,对琼脂糖凝胶电泳中出现2条电泳条带的样品应用荧光标记毛细管电泳基因片段分析方法进行脊髓小脑共济失调致病基因三核苷酸(CAG)重复序列突变检测并精确计数,最后经pUC18-T载体克隆测序验证重复次数达异常范围的样本。结果仅发现1例表现为轻度脊髓小脑共济失调和可疑癫癎发作的女性患者具有DRPLA基因CAG重复扩展突变。基因片段分析2个等位基因的CAG重复次数分别为14和54次,克隆测序重复次数为15和58次。其家系另2例成员均有癫癎发作史,但无明显共济失调表现。19例无异常扩展样本基因片段分析显示CAG重复次数为7～20次,其中9次重复最为常见。结论 DRPLA可能存在临床变异。388例脊髓小脑共济失调患者中仅发现1例DRPLA,说明该病在中国共济失调患者中相对罕见。在重复突变检测过程中,由于高度重复序列可产生局部二级结构,在复制过程中可能会出现DNA聚合酶的滑动,从而导致扩增产物的不忠实,这一问题在基因片段分析和克隆测序中均存在,且后者在操作过程中还可能出现克隆过程的不稳定,因此基于这两种方法的结果需要相互验证。
Objective To report the clinical features and gene mutation characteristics of a patient with dendritic nucleus pulposus pallidolus atrophy (DRPLA). Methods 388 cases of spinocerebellar ataxia (234 cases of autosomal dominant hereditary familial proband and 154 cases of sporadic cases) were preliminarily screened by polymerase chain reaction (PCR). Two agarose gel electrophoresis Band samples were detected by fluorescence-labeled capillary electrophoresis gene fragment analysis of spinocerebellar ataxia pathogenicity gene trinucleotide (CAG) repeat mutation detection and accurate counting, and finally confirmed by pUC18-T vector cloning repeated abnormalities Sample of range. Results Only one female patient with mild spinocerebellar ataxia and suspicious epileptic seizures was found to have a CAG repeat expansion mutation of the DRPLA gene. The number of CAG repeats of the two alleles was 14 and 54 for the gene fragment analysis and 15 and 58 for the cloning and sequencing, respectively. The other two members of the family members have history of epileptic seizures, but no obvious ataxia. 19 cases without abnormal expansion of the sample gene fragment analysis showed that the number of CAG repeat 7 to 20 times, of which 9 times the most common repetition. Conclusion DRPLA may have clinical variation. Only one DRPLA was found in 388 patients with Spinocerebellar ataxia, indicating that the disease is relatively rare in Chinese patients with ataxia. In the process of repeated mutation detection, due to the highly repeatable sequence can produce local secondary structure, DNA polymerase may slide in the replication process, resulting in unfaithful amplification products, a problem in gene fragment analysis and cloning and sequencing , And the latter may also instability in the cloning process during the operation. Therefore, the results based on the two methods need to be mutually verified.