Abstract
Metabolic dysfunction-associated steatotic liver disease (MASLD) is a growing public health concern influenced by both genetic and metabolic factors. Polygenic risk scores (PRSs), which combine the effects of known single-nucleotide polymorphisms (SNPs), may improve early risk stratification. We conducted an observational study on 298 MASLD patients: 148 from a Hepatology Unit and 150 from a Bariatric Surgery Unit. Genotyping was performed for the PNPLA3, TM6SF2, MBOAT7, and GCKR variants. A PRS was calculated and used to stratify patients by genetic risk. Liver fibrosis was assessed using the FIB-4 index, and a subset also underwent transient elastography. Clinical, biochemical, and anthropometric data were analyzed across genetic strata. PRSs showed positive correlations with AST, ALT, and FIB-4, indicating increased liver injury and fibrosis risk with higher genetic burden. Transaminases increased significantly across PRS quartiles (p < 0.05), and individuals with PRS > 0.532 exhibited elevated AST, ALT, and borderline FIB-4. Variant-specific associations included PNPLA3 with increased AST and MBOAT7 with higher hepatic steatosis (CAP). Subgroup analyses revealed distinct genetic and phenotypic patterns between the two clinical cohorts. These findings support the additive role of genetic risk in MASLD progression and underscore the value of polygenic profiling for the early identification and personalized management of high-risk patients.