A dataset of sequential DNA methylation profiles (2 timepoints) of 10 patients with chronic lymphocytic leukemia

Clonal and subclonal evolution is involved in the progression of chronic lymphocytic leukemia (CLL). Evolution can work to select not only genetic mutations, but also epigenetic states. Here we performed a long-term longitudinal DNA methylation profiling study of CLL patients to look for associations of epigenetic evolution to different disease courses. In line with the genetic data, large-scale methylation evolution was not present in any of the evaluated long-term untreated (n = 3) and relapsed (n = 2) patients displaying clonal changes of linear type while 3 of the 5 examined refractory patients featured profound changes in DNA methylation. 20 paired samples of CLL patients (10 patients x 2 timepoints) were analyzed by Illumina Infinium HumanMethylation450 BeadChips. Three patients were long-term untreated at both timepoints, 2 relapsed between the timepoints and 5 developed/maintained refractory disease. Time between consecutive samples ranged from 20 to 108 months.