Genetic Risk Modifiers in DLB Phenotype

SUMMARY

# Genetic Risk Modifiers in DLB Phenotype ## Background and Rationale This large-scale clinical genetics study investigates how genetic risk modifiers influence the clinical phenotype and disease progression in dementia with Lewy bodies (DLB). DLB presents with remarkable phenotypic heterogeneity, with patients exhibiting varying combinations of cognitive decline, visual hallucinations, parkinsonism, and REM sleep behavior disorder. The research focuses on major genetic risk factors including GB

METHODOLOGY NOTES

**Phase 1: Participant Recruitment and Baseline Assessment (Months 1-12)** • Recruit 800 DLB patients from 15 specialized movement disorder centers using McKeith diagnostic criteria • Include 400 age-matched healthy controls and 200 Parkinson's disease controls • Obtain informed consent and collect comprehensive medical histories • Perform standardized clinical assessments: UPDRS-III, MoCA, NPI, CLOX, RBD-SQ, UPSIT • Collect blood samples (10mL EDTA tubes) for genetic analysis • Document current medications and treatment responses using standardized scales **Phase 2: Genetic Analysis and Risk Stratification (Months 6-18)** • Extract genomic DNA using automated systems (minimum 50ng/μL concentration) • Sequence GBA gene (full exonic regions plus 20bp flanking sequences) • Genotype SNCA variants (rs356219, rs11931074, Rep1 microsatellite) • Determine APOE genotype (ε2/ε3/ε4 alleles) using TaqMan assays • Calculate polygenic risk scores using 90 established PD/DLB SNPs • Stratify parti