Exploration of GCase Activity to Identify a Subpopulation Eligible for a Therapeutic Trial in Dementia With Lewy Bodies

Study Overview
=================
Brief Summary
-----------------
This research focuses on the activity of an enzymatic protein: glucocerebrosidase, in dementia with lewy bodies (DLB). Indeed, the mutation of the GBA gene responsible for a decrease in the activity of glucocerebrosidase is the most frequent known genetic risk factor in DLB. However, mutations of the GBA gene are known in another pathology, Gaucher disease, in which treatments have been developed. The objective of this research is to determine if glucocerebrosidase activity is decreased in DLB. This hypothesis could open up a therapeutic perspective, with treatments already used in Gaucher disease.

Detailed Description
-----------------
Population: 118 patients and 118 control subjects Act of research: blood test Objectifs : Comparison of glucocerebrosidase activity between patients and controls Search for variants or mutations of the GBA gene and correlation with glucocerebrosidase activity Correlation between clinical characteristics (UPDRS motor scale, MMSE cognitive scale) and GCase activity in patients

Official Title
-----------------
Exploration of Glucocerebrosidase Activity to Identify a Subpopulation Eligible for a Therapeutic Trial in Dementia With Lewy Bodies

Conditions
-----------------
Dementia With Lewy Bodies

Intervention / Treatment
-----------------
* Diagnostic Test: Glucocerebrosidase
* Genetic: GBA gene


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria for patients : Male or female aged ≥ 50 years old Presence of an accompanying person Dementia with lewy bodies according to the revised criteria of Mc Keith 2017 Inclusion Criteria for controls: Male or female aged ≥ 50 years old Absence of cognitive impairment and clinical element for a neurodegenerative disease Exclusion Criteria for patients: Other neurodegenerative disease Gaucher disease Exclusion Criteria for controls: Neurodegenerative disease Cognitive impairment of all causes

Ages Eligible for Study
-----------------
Minimum Age: 50 Years

Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
Accepts Healthy Volunteers

Study Plan
=================
How is the study designed?
-----------------

Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| DLB patients<br>Dementia with lewy bodies according to the revised criteria of Mc Keith 2017 | Diagnostic Test: Glucocerebrosidase<br>* Blood sample (10ml) for GCase activity<br>Genetic: GBA gene<br>* Blood sample (10ml) for variants or mutations of the GBA gene<br>|
| Control<br>Absence of cognitive impairment and clinical element for a neurodegenerative disease | Diagnostic Test: Glucocerebrosidase<br>* Blood sample (10ml) for GCase activity<br>Genetic: GBA gene<br>* Blood sample (10ml) for variants or mutations of the GBA gene<br>|

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| GCase activity in patients and control by fluorometry | difference in measurement of glucocerebrosidase enzyme activity (by fluorometry method) between DLB patients and control subjects. | through study competion, an average of 1 year | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| GBA gene and GCase activity | correlation between the presence of GBA gene mutation and the measurement of glucocerebrosidase enzymatic activity | through study competion, an average of 1 year | 
| MMSE score and GCase activity | correlation between the measurement of glucocerebrosidase enzymatic activity and MMSE score (Mini-Mental State Examination from 0-severe to 30-normal) of DLB patients | through study competion, an average of 1 year | 
| motor sub-score of UPDRS score and GCase activity | correlation between the measurement of glucocerebrosidase enzymatic activity and motor sub-score of UPDRS score (motor sub-score of Unified Parkinson Disease Rating Scale from) of DLB patients The score is between 0 and 55. The score increases proportionally to the severity of the extrapyramidal syndrome. | through study competion, an average of 1 year | 

 Terms related to the study
=================
Keywords Provided by Centre Hospitalier Valida
-----------------
Glucocerebrosidase, GBA gene