Bi-allelic deletions within 13q14 and transient trisomy 21 with absence of GATA1s in pediatric acute megakaryoblastic leukemia.

Oligonucleotide array comparative genomic hybridization, karyotype and fluorescence in situ hybridization analyses were employed to delineate the cytogenetic abnormalities in a case of pediatric acute megakaryoblastic leukemia. Here we present a unique genetic profile that includes bi-allelic deletions within 13q14, where the retinoblastoma tumor suppressor gene (RB1) resides, as well as isolated trisomy 21 without a concomitant mutation in the hematopoietic transcription factor GATA1s and translocation (17;22), that does not involve the megakaryoblastic leukemia 1 (MKL1) gene located on chromosome 22. Alteration of the RB1 gene is most likely the critical leukemogenic event in this patient.