IntroductionAberrant DNA methylation is one of the important molecular markers in acute lymphoblastic leukemia (ALL). ObjectivesTo determine Aberrant DNA methylation profiles of the CDKN2A and CDKN2B genes in ALL samples from T1DM cases. ResultsAberrant hypermethylation of CDKN2B gene and cytogenetic abnormalities were analyzed in >60% of subjected cases. Total cholesterol, triglycerides and low-density lipoprotein cholesterol were not significantly varied between experimental and control (p >0.05). Expression analysis of human peripheral blood mononuclear cells revealed decreased mRNA levels of CDKN2B. The decreased level of p21 and CDK4 expression in the T1DM cases than control. The number of monocytes, lymphocytes and neutrophils significantly varied in T1DM samples and control (p < 0.05). ConclusionsAberrant methylation is one of the important mechanisms involved in the expression of CDKN2B genes and is an important prognostic marker for the early detection of ALL risks.