Background: Type 1 diabetes mellitus (T1D) is considered as one of the most frequent chronic illnesses in childhood. It results from insulin deficiency due to autoimmune destruction of pancreatic beta cells. The prevalence of T1D in the overall population is 0.4%. People with a 1^st -degree relative diagnosed with T1DM possess an around fifteen-fold elevated relative lifetime probability of developing T1D themselves. Nonetheless, a minimum of eighty-five percent of kids diagnosed with T1D lack a familial history of the condition. Objective: this research aimed to assess if there is a relationship among insulin gene polymorphism & progress of T1D trying for preventing it. Methods: We searched Google Scholar, Science Direct, PubMed and other online databases for T1D, Polymorphism, VNTR INS -23/Hph1 (rs689) and Insulin gene. The authors also reviewed references from pertinent literature, however only the most recent or comprehensive studies from 1991 to 2023 were included. Documents in languages other than English were disqualified due to lack of translation-related sources. Papers such as unpublished manuscripts, oral presentations, conference abstracts, and dissertations that were not part of larger scientific studies were excluded. Conclusion: Polymorphisms in noncoding region of insulin gene impact susceptibility to or protection from T1D. This locus encompasses a VNTR, additionally referred to as the insulin gene mini-satellite, situated at 5' terminus of insulin gene. The VNTR region consists of variable tandem repeat sequences of 14-15 base pairs, with the consensus sequence 5'-ACAGGGGTGTGGGG-3'. 3 primary classes of VNTRs are categorized by their size: Class I (Twenty-six to sixty-three repeats), class II (Around eighty repeats) & class three (140–200 repeats). The insulin gene -23/Hph1 A more than T (rs689) single-nucleotide polymorphism (SNP), a variant within human insulin gene, demonstrated a strong association disequilibrium with variable nucleotide tandem repeat alleles. A allele is associated with the short (class I) VNTR, while T allele is associated with long (Class three) variable nucleotide tandem repeat allele.