DNMT3A mutation p.R882H in JMML patient D101, DNMT3A mRNA expression in JMML mononuclear cells and correlation with promoter DNA methylation. (A) Heterozygous DNMT3A R882H mutation detected in granulocytes but not in Epstein-Barr virus (EBV)–transformed B cells of patient D101. PB indicates peripheral blood. (B) Expression of DNMT3A mRNA was measured by quantitative real-time PCR in mononuclear cells from 9 patients with JMML. Expression in normal controls (n = 4) was averaged and set to 1.0. Each sample was measured in triplicates; error bars denote 1 SD. (C) Expression of DNMT3A mRNA and calcitonin A (CALCA) gene promoter DNA methylation in 6 cases of JMML (methylation data previously published in Olk-Batz et al⁴ ).