Abstract
Background: Congenital biliary dilatation (CBD) is a prevalent congenital biliary disease in children, particularly in Asian populations, yet its etiology remains poorly understood. This study aimed to investigate the genome-wide DNA methylation profile in the peripheral blood of children with CBD to identify potential epigenetic mechanisms involved in its pathogenesis. Methods: Genome-wide DNA methylation profiles were compared between whole blood samples from 37 children with CBD and 24 healthy controls using the Illumina Infinium Human MethylationEPIC (850 K) BeadChip. Bioinformatic analyses were performed to identify differentially methylated positions (DMPs) and regions (DMRs), and functional enrichment analysis was conducted on associated genes. Results: We identified 24,230 differentially methylated sites associated with 5,863 genes. Among these, 8,313 sites were hypermethylated and 15,917 were hypomethylated in CBD patients compared to controls. 54 significant differentially methylated regions (DMRs) were also detected. Functional enrichment analysis revealed that the differentially methylated genes were significantly enriched in key biological pathways, most notably the T cell receptor signaling pathway. Conclusion: This study presents the first comprehensive analysis of genome-wide DNA methylation in CBD, revealing significant epigenetic alterations in peripheral blood. These findings suggest that aberrant DNA methylation, particularly in genes regulating immune pathways, may play a critical role in the development of CBD and could provide valuable insights for identifying novel diagnostic biomarkers.