Patients carrying severe GBA1 mutations showed (1) an earlier age at onset, (2) more pronounced cognitive decline and higher prevalence of rapid eye movement sleep behavior disorder, and (3) reduced CSF levels of total alpha-synuclein.
Using logistic regression (while controlling for sex, age at onset and PD duration), we found that probable REM-sleep behavior disorder (RBD) was significantly more common for GBA-PD than for LRRK2-PD, while none of the GBA-LRRK2-PD patients reported RBD.
Participants belonging to the following cohorts of the Parkinson Progression Markers Initiative (PPMI) study were included: de novo PD with dopamine transporter binding deficit (n = 423), idiopathic REM sleep behavior disorder (RBD, n = 39), hyposmia (n = 26) and non-PD mutation carrier (NMC; Leucine-rich repeat kinase 2 (LRRK2) G2019S (n = 88) and glucocerebrosidase (GBA) gene (n = 38) mutations)).