COG1 is a core subunit of the conserved oligomeric Golgi (COG) complex, an eight-subunit peripheral membrane protein complex essential for Golgi apparatus function 1. COG1 belongs to Lobe A (Cog1-4) of the complex and is required for retrograde vesicle tethering within intra-Golgi trafficking 12. The complex orchestrates protein and lipid glycosylation and protein sorting by controlling retrograde vesicular transport and maintaining normal Golgi morphology and structure 34. COG1 localizes primarily to cisternae tips, rims, and associated vesicles throughout the Golgi apparatus 4. Loss of COG1 function causes congenital disorder of glycosylation type 2G (COG1-CDG), a rare inherited disorder characterized by severe defects in N- and O-glycosylation and Golgi retrograde trafficking 52. Reported COG1-CDG patients present with neonatal seizures, dysmorphism, hepatitis, and abnormal serum transferrin isoforms 5. COG1 mutations also contribute to cardiac manifestations through disrupted carbohydrate metabolism, as COG1 is identified among 29 congenital glycosylation disorder genes associated with cardiomyopathies and cardiac defects 6. COG1 deficiency results in mislocalization or degradation of Golgi glycosyltransferases and glycosidases, causing multi-systemic disease 12.