Insights into the Genetic and Epigenetic Landscape of Endocrine Autoimmunity: A Systematic Review

Background/Objectives: Endocrine autoimmune diseases, including autoimmune thyroid, pituitary, parathyroid, adrenal, and gonadal diseases, result from complex interactions between genetic susceptibility and environmental triggers. Advances in genomics and epigenomics have provided novel insights into the molecular pathways leading to immune dysregulation and endocrine tissue destruction. This review summarizes recent progress in understanding the genetic and epigenetic bases, emphasizing shared and disease-specific mechanisms that contribute to autoimmunity and endocrine dysfunction. Methods: A comprehensive literature search was performed in PubMed, Scopus, and Web of Science up to August 2025, focusing on genome-wide association studies (GWAS), next-generation sequencing, and epigenetic profiling (DNA methylation, histone modification, and non-coding RNA regulation). Results: More than 60 susceptibility loci have been identified across endocrine autoimmune diseases (EADs), including key genes in immune tolerance (HLA, CTLA4, PTPN22) and endocrine-specific pathways. Epigenetic studies reveal that altered DNA methylation and histone acetylation patterns in immune and endocrine cells modulate gene expression without changing the DNA sequence, linking environmental exposures to disease onset. Dysregulated microRNAs further influence immune signaling and cytokine networks. Conclusions: Genetic and epigenetic discoveries highlight the multifactorial nature of EADs and reveal potential biomarkers for early detection and targets for precision immunotherapy. Future research integrating multi-omics and longitudinal analyses will be crucial to unravel causal mechanisms and develop personalized preventive strategies.