GBA1 and Ehlers-Danlos syndrome: A total of 12 studies compared sleep disturbance between patients with and without heterozygous GBA variants (7 studies on the risk of RBD [5, 14, 16, 18, 19, 21, 22], 7 on the RBD Screening Questionnaire (RBDSQ) score [14, 15, 17, 20, 21, 23, 24] and 2 on the risk of EDS [15, 21]).