GBA1 and Lewy body dementia: Clinical studies reported that GBA1-linked PD/DLB is virtually indistinguishable from idiopathic PD/DLB, with a slightly earlier age of onset (Nichols et al., 2009; Gamez-Valero et al., 2016) and higher prevalence of cognitive impairment (Sidransky et al., 2009).