Takiyama Y, Shimazaki H, Morita M, Soutome M, Sakoe K, Esumi E, Muramatsu S, Yoshida M, Igarashi S, Tanaka H, Tsuji S, Sasaki H, Wakisaka A, Nakano I, Nishizawa M
Department of Neurology, Jichi Medical School, Tochigi, Japan.
J Neurol Sci. 1998 Mar 5;155(2):141-5. doi: 10.1016/s0022-510x(98)00012-4.
We studied the relationship between the number of CAG repeat units in the MJD1 gene and clinical features of Machado-Joseph disease (MJD) in eight patients from two generations of a Japanese MJD family. Because of lack of characteristic clinical signs of MJD such as dystonia, bulging eyes or facial myokymia, clinical diagnosis of MJD in this family was difficult to make prior to molecular testing for the CAG repeat expansion in the MJD1 gene. All the patients exhibited maternal transmission of MJD, and the intergenerational change in the number of CAG repeat units in the MJD1 gene was very small (+0.5+/-0.3, mean+/-S.E.M., n=4) in spite of marked genetic anticipation (-17.0 years/generation). In the present family, the degree of anticipation per repeat unit in maternal transmissions was much larger than that in maternal transmissions in the other six MJD families. This indicates that some maternal factors other than the increase of the number of CAG repeat units, which is known to be the basis of anticipation, may play a role in genetic anticipation in this MJD family.
我们研究了来自一个日本马查多-约瑟夫病（MJD）家族两代人的8例患者中，MJD1基因中CAG重复序列单位数量与马查多-约瑟夫病临床特征之间的关系。由于缺乏MJD的特征性临床体征，如肌张力障碍、突眼或面部肌束震颤，在对MJD1基因中的CAG重复序列扩增进行分子检测之前，该家族中MJD的临床诊断很难做出。所有患者均表现出MJD的母系遗传，尽管存在明显的遗传早现现象（-17.0年/代），但MJD1基因中CAG重复序列单位数量的代际变化非常小（+0.5±0.3，平均值±标准误，n = 4）。在本家族中，母系遗传中每个重复序列单位的早现程度远大于其他6个MJD家族的母系遗传。这表明，除了已知作为早现基础的CAG重复序列单位数量增加之外，某些母系因素可能在这个MJD家族的遗传早现中发挥作用。
