GPT and Parkinson disease: The aspartate aminotransferase (AST) to alanine aminotransferase (ALT) ratio has emerged as a potential indicator of neurodegenerative processes, yet its relationship with PD genetic subtypes remains unexplored.<h4>Objective</h4>This study aims to investigate the relationship between the AST to ALT ratio (AST/ALT) and different genetic subtypes of PD.<h4>Methods</h4>This retrospective analysis included 1315 PD patients (1005 sporadic, 310 familial) from Parkinson's Progression Markers Initiative (PPMI) databases.