Clinical significance of aberrant DNA methylation in childhood acute lymphoblastic leukemia

Methylation profile was analyzed in ninety-five patients with childhood acute lymphoblastic leukemia (ALL). Methylation of both MGMT and p16 genes were associated with higher age (p = 0.01 and p = 0.03, respectively). Methylation of both p15 and SHP1 genes occurred more frequently in T-ALL than in precursor B-ALL (p = 0.02 and p = 0.01, respectively). In contrast, methylation of the DAPK gene was more frequent in precursor B-ALL (p = 0.01). Patients with methylation of multiple genes more likely had T cell phenotype, and are classified as medium/high risk (p = 0.004 and p = 0.03, respectively). These results suggest that methylation status is associated with clinicopathological features in childhood ALL.