en عمومى Human Genetics مروری Review <span style="font-size:12pt"><span style="line-height:150%"><span new="" roman="" style="font-family:" times="">Diabetes mellitus, encompassing type 1 (T1D) and type 2 diabetes (T2D), is a major global health burden with rapidly increasing prevalence. T1D is characterized by autoimmune destruction of pancreatic &beta;-cells, whereas T2D primarily involves insulin resistance and &beta;-cell dysfunction. Despite advances in clinical and molecular research, gaps remain in understanding the genetic architecture and gene&ndash;environment interactions driving disease onset and progression. This review summarizes current evidence on genetic polymorphisms associated with T1D and T2D, with a focus on their roles in disease susceptibility, complications, and potential therapeutic implications. In T1D, variants in the HLA region, INS, and PTPN22 have been strongly linked to autoimmunity and &beta;-cell vulnerability. In T2D, genes such as TCF7L2, KCNJ11, SLC30A8, and EPO influence insulin secretion, glucose homeostasis, and risk modulation, with loss-of-function mutations in SLC30A8 showing protective effects. Emerging data highlight how genetic variants interact with zinc metabolism, inflammatory pathways, and environmental factors to shape disease heterogeneity. Additionally, polymorphisms in both T1D- and T2D-associated genes contribute to the risk of long-term complications, including nephropathy, retinopathy, and cardiovascular disease. By integrating evidence from genome-wide association studies, next-generation sequencing, and functional analyses, this review emphasizes the diagnostic and prognostic value of genetic markers. Understanding these genetic insights not only enhances risk prediction and early diagnosis but also supports the development of precision medicine approaches tailored to individual genetic backgrounds.</span></span></span><br> &nbsp; Polymorphism, Genetic, Diabetes Mellitus, Type 1, Diabetes Mellitus, Type 2, Insulin-Secreting Cells, Precision Medicine. 0 0 http://humangeneticsgenomics.ir/browse.php?a_code=A-10-389-4&slc_lang=en&sid=1 Darya Taromi Rezaie darya.taromi@gmail.com 10031947532846001187 10031947532846001187 No Department of Biochemistry and Biophysics, TeMS.C., Islamic Azad University, Tehran, Iran. Ameneh Mohammadi aynaz.mohammadi6868@gmail.com 10031947532846001188 10031947532846001188 No Department of Biochemistry and Biophysics, TeMS.C., Islamic Azad University, Tehran, Iran. Fereshteh Atabi feratabi@gmail.com 10031947532846001189 10031947532846001189 Yes Department of Biochemistry and Biophysics, TeMS.C., Islamic Azad University, Tehran, Iran. Mahdi Moassesfar mmoasesfar@gmail.com 10031947532846001190 10031947532846001190 No Department of Biochemistry and Biophysics, TeMS.C., Islamic Azad University, Tehran, Iran.