Genotype-associated outcomes after deep brain stimulation in Parkinson’s disease: a systematic review, meta-analysis and epigenetic implications

At approximately 12 months, motor improvement after DBS appears broadly comparable between genotype- -defined variant carriers and non-carriers, with the most consistent evidence available for GBA1. Inference - particularly for cognition and quality of life - is constrained by gene/variant heterogeneity, observational study design, and the predominance of subthalamic nucleus-DBS (STN-DBS) cohorts. Clinical epigenetic predictors of DBS response remain unstudied, supporting the need for hypothesis-driven, genotype-stratified biomarker cohorts.