Department of Neurology, University of Texas Southwestern Medical Center, Dallas, Texas, USA,
Department of Neurology, University of Texas Southwestern Medical Center, Dallas, Texas, USA.
Neuroepidemiology. 2022;56(5):373-379. doi: 10.1159/000526278. Epub 2022 Aug 8.
Essential tremor (ET) is a highly prevalent neurological disease that frequently runs in families. A recent and controversial proposal is to separate ET patients into two distinct groups - ET versus ET-plus. If this were a valid construct, one would expect in familial aggregation studies to observe that ET-plus would cluster in some families yet be absent in others, rather than being randomly distributed across families. We examined whether there is evidence of familial aggregation of ET-plus.
Probands (n = 84 [56 ET-plus and 28 ET]) and their first- and second-degree relatives (n = 182 and 48) enrolled in a genetics study. χ2 and generalized estimating equations (GEE) tested associations between probands' ET-plus status and the ET-plus status of their relatives.
χ2 analyses revealed that ET-plus was no more prevalent in relatives of probands diagnosed with ET-plus than in relatives of probands diagnosed with ET, p > 0.05. Restricting relatives to first-degree relatives similarly did not detect a significant association (p = 0.88). GEE yielded similar results (respective p's = 0.39 and 0.81).
The data demonstrate that ET-plus does not seem to aggregate in families. As such, they do not lend support to the notion that ET-plus is a valid biological construct.
特发性震颤（ET）是一种高发的神经系统疾病，常呈家族聚集性发病。最近有一个有争议的观点，即把 ET 患者分为两个不同的群体——ET 型和 ET+型。如果这一观点成立，那么在家族聚集性研究中，人们应该观察到 ET+型会在某些家族中聚集，而在其他家族中缺失，而不是随机分布在各个家族中。我们研究了 ET+型是否存在家族聚集性。
在一项遗传学研究中，我们招募了 84 名患者（56 名 ET+型和 28 名 ET 型）及其一级和二级亲属（182 名和 48 名）。卡方检验和广义估计方程（GEE）检验了先证者 ET+型与亲属 ET+型之间的关联。
卡方分析显示，先证者被诊断为 ET+型的亲属中，ET+型的患病率并不高于先证者被诊断为 ET 型的亲属，p>0.05。将亲属限定为一级亲属也未发现显著关联（p=0.88）。广义估计方程也得到了类似的结果（分别为 p=0.39 和 p=0.81）。
这些数据表明，ET+型似乎不会在家族中聚集。因此，它们不支持 ET+型是一个有效的生物学概念的观点。
