Exploring the link between GBA1 mutations and Dementia with Lewy bodies, A mini-review.

IMPORTANCE: Dementia with Lewy bodies (DLB) is a neurodegenerative disease linked to abnormal accumulation of phosphorylated α-synuclein. GBA1 is the gene encoding the lysosomal enzyme glucocerebrosidase (GCase), whose mutations are a risk factor of DLB. OBJECTIVE: To report all available data exploring the association between GBA1 mutations and DLB. EVIDENCE REVIEW: All publications focused on GCase and DLB in humans between 2003 and 2022 were identified on PubMed, Cochrane and ClinicalTrials.gov. FINDINGS: 29 studies were included and confirmed the strong association between GBA1 mutations and DLB (Odds Ratio [OR]: 8.28). GBA1 mutation carriers presented a more malignant phenotype, with earlier symptom onset, more severe motor and cognitive dysfunctions, more visual hallucinations and rapid eye movement sleep disorder. GBA1 mutations were associated with "purer" neuropathological DLB. No therapeutic recommendations exist and clinical trials targeting GCase are just starting in DLB patients. CONCLUSIONS AND RELEVANCE: This review reports a link between GBA1 mutations and the DLB phenotype with limited evidence due to the small number of studies.

Cerebrospinal fluid Alzheimer biomarkers can be useful for discriminating dementia with Lewy bodies from Alzheimer's disease at the prodromal stage.

BACKGROUND: Differential diagnosis between dementia with Lewy bodies (DLB) and Alzheimer's disease (AD) is not straightforward, especially in the early stages of disease. We compared AD biomarkers (phospho-Tau181, total-Tau, Aß42 and Aß40) in cerebrospinal fluid (CSF) of patients with DLB and AD, focusing especially on the prodromal stage. METHODS: A total of 1221 CSF were collected in different memory centres (ePLM network) in France and analysed retrospectively. Samples were obtained from patients with prodromal DLB (pro-DLB; n=57), DLB dementia (DLB-d; n=154), prodromal AD (pro-AD; n=132) and AD dementia (n=783), and control subjects (CS; n=95). These centres use the same diagnostic procedure and criteria to evaluate the patients. RESULTS: In patients with pro-DLB, CSF Aß42 levels appeared much less disrupted than in patients at the demented stage (DLB-d) (P<0.05 CS>pro-DLB; P<0.001 CS>DLB-d). On average, Aß40 levels in patients with DLB (pro-DLB and DLB-d) were much below those in patients with pro-AD (P<0.001 DLB groups