  The possibility of targeting the causal genes along with the mechanisms of
pathogenically complex diseases has led to numerous studies on the genetic
etiology of some diseases. In particular, studies have added more genes to the
list of type 1 diabetes mellitus (T1DM) suspect genes, necessitating an update
for the interest of all stakeholders. Therefore this review articulates T1DM
suspect genes and their pathophysiology. Notable electronic databases,
including Medline, Scopus, PubMed, and Google-Scholar were searched for
relevant information. The search identified over 73 genes suspected in the
pathogenesis of T1DM, with human leukocyte antigen, insulin gene, and cytotoxic
T lymphocyte-associated antigen 4 accounting for most of the cases. Mutations
in these genes, along with environmental factors, may produce a defective
immune response in the pancreas, resulting in \b{eta}-cell autoimmunity,
insulin deficiency, and hyperglycemia. The mechanisms leading to these cellular
reactions are gene-specific and, if targeted in diabetic individuals, may lead
to improved treatment. Medical practitioners are advised to formulate treatment
procedures that target these genes in patients with T1DM.
