Aberrant methylation in promoter-associated CpG islands of multiple genes in acute lymphoblastic leukemia

Methylation profile was analyzed in 10 childhood acute lymphoblastic leukemia (ALL) and nine adult ALL cases. Four genes (p15, p16, RARβ, FHIT) had methylation in both diseases, four genes (p14, Rb, MLH1, DAPK) showed no methylation in both diseases, and the two genes (APC, RIZ) demonstrated methylation only in adult ALL. Methylation of the RARβ was more frequent in adult ALL than that in childhood ALL (p = 0.01). The number of patients with methylation of multiple genes was higher in adult ALL than that in childhood ALL (p = 0.006). Moreover, overall frequency of methylation was higher in adult ALL than that in childhood ALL (p = 0.01).