Whole Genome Sequencing to track subclonal heterogeneity in 18 samples from 3 Chronic Lymphocytic Leukemia patients subjected to repeated cycles of therapy.

This study took 18 samples from three patients with Chronic Lymphocytic Leukemia. The 3 CLL patients received multiple different treatments sequentially for a period of up to 7 years. Peripheral blood samples were taken at 5 specific time points during disease progression together with 1 matched buccal swab per patient. All the selected patients had unmutated IgVH status reflecting poor prognosis. However, none of the patients had complex genomic aberrations associated with aggressive disease. Peripheral blood samples and buccal smears were obtained from patients, who had given informed consent for sequential sample collection and analysis. Tumour samples were obtained before treatment, after treatment and at relapse and subjected to Ficoll separation. Lymphocyte cell purity was assessed by full blood count enumeration. Buccal smears were obtained and processed using Isohelix.EGA study EGAS00001000885