New study aims to unravel Parkinson's protein mysteries

Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.

Inclusion criteria for Parkinson's disease cohorts (GBA-PD and nonGBA-PD): * Diagnosis of PD according to MDS-PD criteria and, for the GBA-PD group, presence of heterozygous GBA mutations (with a balanced distribution of severe, risk, mild, and complex variants); * Disease duration between 3 and 7 years; * Disease stage according to Hoehn \& Yahr ≤ 3; * Absence of mutations in other known genes associated with PD susceptibility; * Age \> 18 Years; * Ability to understand and voluntarily sign informed consent and to comply with study procedures. Exclusion criteria for Parkinson's disease cohorts: * Diagnosis of atypical and/or secondary parkinsonism; * Diagnosis of dementia according to DSM-5 criteria; * Presence of other neurological disorders and/or essential tremor; * Presence of systemic inflammatory or infectious diseases, autoimmune diseases, or malignant tumors at the time of enrollment. Inclusion criteria for unaffected subjects (GBA-nonPD and nonGBA-nonPD): * Age \> 18 Years; * Ability to understand and voluntarily sign informed consent and to comply with study procedures; * No diagnosis of PD or other neurological disorders; * Presence of a heterozygous GBA mutation for the GBA-nonPD group and absence of such mutation for control subjects (nonGBA-nonPD); * Absence of mutations in other known genes associated with PD susceptibility. Exclusion criteria for unaffected subjects (GBA-nonPD and nonGBA-nonPD): * Presence of systemic inflammatory or infectious diseases, autoimmune diseases, or malignant tumors at the time of enrollment; * Diagnosis of atypical and/or secondary parkinsonism; * Diagnosis of dementia according to DSM-5 criteria. Inclusion criteria for subjects with idiopathic REM Sleep Behavior Disorder (GBA-iRBD and nonGBA-iRBD): * Diagnosis of idiopathic REM Sleep Behavior Disorder according to ICSD-3; * Age \> 18 Years; * Ability to understand and voluntarily sign informed consent and to comply with study procedures; * No diagnosis of PD or other neurological disorders; * Presence of a heterozygous GBA mutation for the GBA-iRBD group and absence of such mutation for the nonGBA-iRBD group; * Absence of mutations in other known genes associated with PD susceptibility. Exclusion criteria for subjects with idiopathic REM Sleep Behavior Disorder (GBA-iRBD and nonGBA-iRBD): * Presence of systemic inflammatory or infectious diseases, autoimmune diseases, or malignant tumors at the time of enrollment; * Diagnosis of atypical and/or secondary parkinsonism; * Diagnosis of dementia according to DSM-5 criteria.