Simple SummaryDiabetes has a high mortality rate. Diabetes mellitus is a state of hyperglycemia or high glucose levels caused by the inability of the body to produce insulin, insulin resistance, or both. One of the causes of diabetes is the occurrence of mutations in mitochondrial genome genes and the loss of transfer RNA modification. Transfer RNA genes are part of the mitochondrial DNA genome that act as adapters and are key for protein synthesis. In this review, we discuss the structure of transfer RNA, mutations associated with and their relation to various diseases, as well as mutations associated with type 2 diabetes mellitus. In addition, methods that have been used to identify mutations and ideas for treatment are discussed.AbstractTransfer RNA (tRNA) genes in the mitochondrial DNA genome play an important role in protein synthesis. The 22 tRNA genes carry the amino acid that corresponds to that codon but changes in the genetic code often occur such as gene mutations that impact the formation of adenosine triphosphate (ATP). Insulin secretion does not occur because the mitochondria cannot work optimally. tRNA mutation may also be caused by insulin resistance. In addition, the loss of tRNA modification can cause pancreatic β cell dysfunction. Therefore, both can be indirectly associated with diabetes mellitus because diabetes mellitus, especially type 2, is caused by insulin resistance and the body cannot produce insulin. In this review, we will discuss tRNA in detail, several diseases related to tRNA mutations, how tRNA mutations can lead to type 2 diabetes mellitus, and one example of a point mutation that occurs in tRNA.