Abstract
We had an opportunity to analyse banked cord blood samples from two patients with childhood ALL; the work has been approved by the Ethical committee of University Hospital Motol and subjects/guardians gave informed consent to the study. The first case was hyperdiploid BCP-ALL diagnosed at 3.7 years of age with pre-B immunophenotype (CD10+, CD19+, CD34+, CD38+, cytoplasmatic IgM+), DNA index 1.58 and gain of chromosomes 4, 7, 9, 12, 16, 17, 18, 20, 21 and X.
The second child was diagnosed at the age of 4.9 with T-ALL presenting with only 30% of blasts in the bone marrow and suffered a very early relapse of the disease (90% of blasts) 11 months later with all the Ig/TCR markers and CDKN2A deletion (the only copy number change detected using comparative genomic hybridisation) maintained between the diagnosis and relapse. The patient was negative for all other T-ALL recurrent changes tested (TCR, HOX11, HOX11L2, LMO2, MLL, BCR/ABL, SIL/TAL, CALM/AF10 translocations, ABL1 amplification) with the exception of NOTCH1 mutation (deletion of 6 nucleotides in exon 26) present at the relapse of the disease.