PRKN and Ehlers-Danlos syndrome: However, our pooled analysis of cross-sectional studies showed no correlation between PRKN variant and the risk and severity of sleep disturbances including RBD [7, 8, 15, 37–40], EDS [7, 8, 15, 37, 38, 40] and RLS [7, 8, 40] in patients with PD.