Type 1 diabetes mellitus (T1DM) is an autoimmune disorder that typically manifests in early childhood but can occur in persons of any age. The condition is a result of autoreactive T lymphocytes that target and destroy insulin-producing beta cells in the pancreatic islet. This results in a complete lack of insulin and persistently high blood sugar levels, necessitating lifelong insulin treatment. For the present experiment, five groups were selected, all of whom were volunteers. Four cohorts of T1DM patients were categorized based on their age, whereas the fifth cohort consisted of individuals without diabetes. The HLA-DRB1*03 exon 2 allele's bidirectional sequencing was established using blood samples. PCR was employed to determine the gene sequence, amplify it, and extract the gene for DNA sequencing in both forward and reverse directions. The sequencing output data was subjected to bioinformatics analysis to get insights into the isolated gene and its function in T1DM. In addition, specific software applications were utilized to forecast the translated protein and RNA secondary structures. A modification occurred in the secondary structure of RNA, which had an impact on the translation and release of proteins in somatic cells. Furthermore, the SNP analysis indicated that the targeted genes in the four groups exhibited changes resulting from the substitution or deletion of certain nucleotides. These mutations altered the predicted protein translation in the sick groups as compared to the control group.