This study explores how a protein called glucocerebrosidase works in people with dementia with Lewy bodies (DLB). A gene called GBA can change how this protein works, and these changes can increase the risk of DLB. The study aims to see if this protein works less effectively in DLB patients, as it does in another disease called Gaucher disease, where treatments already exist. Researchers will collect blood samples from 118 patients and 118 healthy volunteers. They will compare protein activity, look for genetic changes, and see how these relate to clinical signs like movement and thinking abilities. The study will also examine if certain cell behaviors are affected and how treatments might help.

• The study requires only one blood test from participants.
• Participants must be at least 50 years old and have no other neurodegenerative diseases.
• No direct treatment is given during this study, but it may lead to future treatment options.