GBA1 and Parkinson disease: The severity of motor and non-motor impairments, as well as the rate of disease progression, are variable and can be influenced by factors such as medication regimen, presence of sleep disturbances like rapid eye movement sleep behavior disorder (RBD), hyposmia, and genetic mutations like those in the GBA1 gene (GBA1-associated PD) (Aarsland et al., 2021; Haehner et al., 2019; Kang et al., 2016; Roeben et al., 2024).