脊髓小脑共济失调3型的产前诊断方法研究

Research on prenatal diagnosis methods of spinocerebellar ataxia type 3/Machado-Joseph disease

目的 探讨基于羊水细胞培养和毛细管电泳片段分析技术的脊髓小脑共济失调3型（SCA3/MJD）的产前诊断方法。方法 对1例孕20周的确诊SCA3/MJD患者及8名孕16~19周的高龄孕妇进行羊膜穿刺术并抽取羊水细胞培养。采用毛细管电泳片段分析技术对MJD1基因内（CAG）n重复序列动态突变进行检测。结果 SCA3/MJD患者胎儿MJD1基因（CAG）n次数为22/78次,胎儿携带其母亲的异常等位基因,诊断为SCA3/MJD。8例高龄孕妇胎儿MJD1基因（CAG）n重复次数13~26次,均在正常范围内。结论羊水细胞培养并毛细管电泳片段分析技术简便,准确,可作为SCA3/MJD产前诊断的可靠方法进一步推广。

Objective To explore the prenatal diagnosis methods of spinocerebellar ataxia type 3 （SCA3）/ Machado-Joseph disease （MJD） based on amniotic fluid cells culturing and fragment analysis with capillary electrophoresis. Methods The amnioeentesis and aminotic cell culture were performed in a SCA3/MJD pregnant women at 20 weeks of gestation and 8 pregnant women at 16 - 19 weeks of gestation. The MJD1 gene （CAG） n dynamic mutation were detected by capillary eleetrophoresis separation. Results The number of MJD1 gene （CAG） n in fetal of SCA3/MJD patient was 22/78, the fragments of abnormal alleles was come from his mother. The fetus was diagnosed with SCA3/MJD. The number of MJD1 gene （CAG）n in fetal of 8 controls were 13 -26, they were in normal range. Conclusions Amniotic fluid cells culturing and fragment analysis with capillary electrophoresis are very simple and precise methods. It worths to be recommended as a promising protocol for SCA3/MJD＇s prenatal diagnosis and genetic consultation.