Citations

Abstract Background: Metabolic-associated fatty liver disease (MAFLD) is a common liver disease and may become the leading cause of severe liver disease in the future. The Global Burden of Disease (GBD) study assesses MAFLD’s impact in countries and regions worldwide, providing insights into its prevalence. Methods: Prevalence data for MAFLD from 1990 to 2021 by country and region in all sex and age groups were collected from the Global Health Data Exchange. The categorization of countries and geographic areas by development was performed using the Sociodemographic Index (SDI). Results: Between 1990 and 2021, the global crude prevalence rate of MAFLD increased from 10.6% to 16.1% (beta-coefficient: 0.2%, 95% confidence interval [CI]: 0.2–0.2%, P <0.001), and the age-standardized prevalence rate was increased from 12.1% to 15.0% (beta-coefficient: 0.1%, 95% CI: 0.1–0.1%, P <0.001). In 2021, MAFLD was estimated to have affected 1.3 billion people worldwide. Significant uptrends were observed in all regions, super regions, and SDI categories. The fastest increase from 1990 to 2021 and the highest prevalence rate in 2021 were experienced by countries and territories with high–middle and middle SDI. An increase in the prevalence of MAFLD from 1990 to 2021 was demonstrated in all but six countries. Conclusions: In 2021, the number of patients affected by MAFLD was doubled compared to 1990, and the prevalence rate increased by over 50%. The burden of MAFLD, as measured by prevalence, was more prominent in countries and territories with middle SDI and in those located in North African and Middle Eastern, possibly due to changes in lifestyle in these areas over the past 30 years.

Pontocerebellar hypoplasia (PCH) is a group of rare neurodevelopmental disorders with limited diagnostic and therapeutic options. Mutations in WDR11, a subunit of the FAM91A1 complex, have been found in patients with PCH-like symptoms; however, definitive evidence that the mutations are causal is still lacking. Here, we show that depletion of FAM91A1 results in developmental defects in zebrafish similar to that of TBC1D23, an established PCH gene. FAM91A1 and TBC1D23 directly interact with each other and cooperate to regulate endosome-to-Golgi trafficking of KIAA0319L, a protein known to regulate axonal growth. Crystal structure of the FAM91A1–TBC1D23 complex reveals that TBC1D23 binds to a conserved surface on FAM91A1 by assuming a Z-shaped conformation. More importantly, the interaction between FAM91A1 and TBC1D23 can be used to predict the risk of certain TBC1D23-associated mutations to PCH. Collectively, our study provides a molecular basis for the interaction between TBC1D23 and FAM91A1 and suggests that disrupted endosomal trafficking underlies multiple PCH subtypes.