G6PD and G6PD deficiency: The present study aims to provide a comprehensive global analysis of G6PD deficiency from 1990 to 2021, using GBD 2021 data to: (1) Characterize global, regional, and national trends in G6PD deficiency prevalence, incidence, and disability burden; (2) Assess the association between G6PD burden and the Socio-Demographic Index (SDI) to understand disparities across different development levels.