Fig. 1

DNA methylation analysis of 34 genes in 45 children with JMML and 11 healthy controls. a Candidate genes for analysis of CpG island methylation in JMML. b CREBBP, MPO, and SLC12A8 were recurrently hypermethylated in JMML. CpG methylation of the indicated target regions was determined in granulocyte DNA from children with JMML and healthy control subjects using quantitative mass spectrometry. The average level of methylation across all CpG units is shown for each sample. A JMML sample was categorized as hypermethylated if the methylation level exceeded three standard deviations above the mean observed in healthy controls. The upper limit of normal methylation is illustrated by a dotted line. The significance of differences was calculated using the Mann-Whitney test and is indicated as follows: *p ≤ 0.0014 (Bonferroni threshold for significance level p ≤ 0.05 after correction for 36 tests, i.e., 34 genes plus HIC1 CpG 3359 and TCF4 CpG 1515); ns, p > 0.0014. c The HIC1 and TCF4 genes had normal methylation in JMML when averaging all CpG units in the region of analysis, but each region contained a single CpG unit with significant hypermethylation in JMML