Reply: Chorea‐acanthocytosis: Report of two Brazilian cases
Reply: Chorea‐acanthocytosis: Report of two Brazilian cases
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答复：舞蹈症棘红细胞增多症：巴西两例报告
DOI：
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发表时间：
2009
期刊：
影响因子：
--
通讯作者：
V. Tumas
中科院分区：
文献类型：
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作者：
Guilherme R. Rodrigues;R. Walker;B. Bader;A. Danek;W. Marques;V. Tumas
我们怀着极大的兴趣阅读了McNicoll及其同事的文章，他们调查了亨廷顿病(HD)基因中CAG重复序列的大小与家族性帕金森病(PD)发病年龄之间的潜在关联。作者推测，由于线粒体功能的指标--ATP/ADP比值在正常范围内受HD CAG重复数的影响，而且线粒体功能障碍与PD的发病机制有关，HD CAG重复数可能与PD的发病年龄有关。尽管作者得出结论，HD CAG重复大小不能改变家族性PD的发病年龄，但我们认为他们并没有令人满意地排除两个HD等位基因中CAG重复大小之间潜在交互作用对发病年龄的影响。作者通过在较大等位基因的CAG重复长度的中位数上对他们的患者队列进行二分法，并将两个等位基因中CAG重复长度的总和作为解释变量来测试可能的交互作用。然而，这些方法在检测任何相互作用的影响方面只有适度的统计能力。对两个变量之间的统计交互作用进行测试的最常见、最有效的方法是同时测试这两个变量及其乘积项。在这种情况下，这将需要输入较大的重复大小、较小的重复大小以及两个重复大小的乘积作为所使用的广义估计方程模型中的预测变量。此外，通过这种方式，可以评估相互作用的影响，同时考虑到家庭内的重复观察。在HD中，正常和扩大的CAG重复序列的大小之间的相互作用已经被证明影响疾病的发病年龄。正如在帕金森病中一样，两个重复序列的大小差异要小得多，我们认为，在假设HD CAG重复序列大小不会改变帕金森病的发病年龄之前，令人满意地排除两个重复序列大小之间的潜在交互影响将是非常重要的。
We read with great interest the article by McNicoll and colleagues who investigated a potential association between the size of the CAG repeat sequence in the Huntington’s disease (HD) gene and age of onset in familial Parkinson’s disease (PD). The authors hypothesized that as the ATP/ADP ratio, a measure of mitochondrial function, is influenced by the HD CAG repeat sizes in the normal range, and as mitochondrial dysfunction has been implicated in PD pathogenesis, HD CAG repeat size might be related to age of disease onset in PD. Although the authors conclude that HD CAG repeat size does not modify onset age in familial PD, we feel that they have not satisfactorily excluded the influence on age of onset of a potential interaction between the CAG repeat sizes in the two HD alleles. The authors tested for possible interaction effects by dichotomizing their patient cohort at the median CAG repeat size of the larger allele, and by using the sum of the CAG repeat sizes in both alleles as an explanatory variable. However, these methods have only modest statistical power in detecting any interaction effects. The most common, and powerful, way for testing for a statistical interaction between two variables is to test simultaneously for both variables and their product term. In this case, this would entail entering of the larger repeat size, the smaller repeat size, as well as the product of the two repeat sizes as predictor variables in the generalized estimating equation model that was used. Additionally, in this way, the effect of the interaction can be assessed while at the same time accounting for the repeated observations within a family. In HD, interaction between the sizes of the normal and expanded CAG repeats has been shown to affect age of disease onset. As in PD, the sizes of the two repeats diverge much less, it would be, in our opinion, very important to satisfactorily exclude a potential interaction effect between the two repeat sizes before assuming that the HD CAG repeat size does not modify age of onset in PD.
影响因子：
3.5
作者：
Seong, IS;Ivanova, E;MacDonald, ME
通讯作者：
MacDonald, ME