only marginally significantp = 0.13
The PD relatives had a modestly increased risk of having ET, although this increased risk was only marginally significant—45 of 2980 (1.5%) first-degree relatives of PD patients had ET vs. 31 of 2981 (1.0%) first-degree relatives of controls (HR = 1.44, 95% CI -= 0.90–2.29, p = 0.13) [ 62 ].