Zhou Y X, Takiyama Y, Igarashi S, Li Y F, Zhou B Y, Gui D C, Endo K, Tanaka H, Chen Z H, Zhou L S, Fan M Z, Yang B X, Weissenbach J, Wang G X, Tsuji S
Neurology. 1997 Feb;48(2):482-5. doi: 10.1212/wnl.48.2.482.
Machado-Joseph disease (MJD) is an autosomal dominant neurodegenerative disorder associated with the expansion of a (CAG)n array in the MJD1 gene. We analyzed the sizes of the (CAG)n array using DNA samples from 61 members of four Chinese MJD families and 18 Chinese normal control subjects and confirmed that the (CAG)n array in 15 MJD chromosomes was expanded to 72-86 repeat units. There were no subjects with (CAG)n array sizes intermediate between those of normal and MJD affected groups. Meanwhile, we found a significant negative correlation between the age of onset of symptoms and (CAG)n array size. The largest (CAG)n array of 86 repeat units was in the youngest patient, whose age of onset was 5 years. The intergenerational increase in number of CAG repeat units was associated with the clinical phenomenon of anticipation.
马查多-约瑟夫病（MJD）是一种常染色体显性神经退行性疾病，与MJD1基因中（CAG）n序列的扩增有关。我们使用来自四个中国MJD家族的61名成员以及18名中国正常对照者的DNA样本分析了（CAG）n序列的大小，证实15条MJD染色体中的（CAG）n序列扩增至72 - 86个重复单位。没有受试者的（CAG）n序列大小处于正常组和MJD受累组之间的中间值。同时，我们发现症状发作年龄与（CAG）n序列大小之间存在显著负相关。最大的含有86个重复单位的（CAG）n序列出现在最年轻的患者中，其发病年龄为5岁。CAG重复单位数量的代际增加与遗传早现的临床现象相关。
