Dicentric (19;21)(p13;p13), a novel chromosomal abnormality occurring in a case of Philadelphia chromosome–positive acute lymphoblastic leukemia

A possible 5'-NRIP1/UHRF1-3' fusion gene detected by array CGH analysis in a Ph+ ALL patient

A translocation between chromosomes 19 and 21 [dic/t(19;21)(p13;v)] is very rare. To date, only three cases of this particular chromosomal abnormality have been reported. The translocations in these three cases were secondary changes in acute lymphoblastic leukemia (ALL) patients with the t(9;22) translocation. The gene(s) at the breakpoints of either chromosome 19p13 or 21q have not yet been identified. Here, we present a case study of a 21-year-old female with a diagnosis of precursor B cell ALL, with the t(9;22) translocation and secondary changes including a der(19)t(19;21) and an extra Philadelphia (Ph+) chromosome [der(22)t(9;22)]. Array comparative genomic hybridization (aCGH) analysis identified UHRF1 and NRIP1 as genes that were interrupted at the breakpoints of 19p13.3 and 21q21.1, and joined together as a possible fusion gene, 5'-NRIP1/UHRF1-3', on the derivative chromosome 19. To our knowledge, this is the first description of possible genes involved in the unbalanced translocation between chromosomes 19 and 21 in a patient with an ALL-positive for a t(9;22) translocation.