Juvenile myelomonocytic leukemia with t(7;11)(p15;p15) and NUP98‐HOXA11 fusion

The t(7;11)(p15;p15) translocation has been reported as a rare and recurrent chromosomal abnormality in acute myeloid leukemia (AML) patients. The NUP98‐HOXA9 fusion gene with t(7;11)(p15;p15) was identified and revealed to be essential for leukemogenesis and myeloproliferative disease. To date, t(7;11)(p15;p15) with NUP98‐HOXA11 fusion has been reported only in one case of ph‐negative chronic myeloid leukemia (CML). Here, we report a case of a 3‐year‐old girl with juvenile myelomonocytic leukemia (JMML) carrying t(7;11)(p15;p15) abnormality with NUP98‐HOXA11 fusion. AML chemotherapy followed by bone marrow transplantation (BMT) was found to be effective in treating this disorder, and she remains in complete remission for 3 years after BMT. We suggest the possibility that AML chemotherapy might be effective for treating JMML with t(7;11)(p15;p15) abnormality and NUP98‐HOXA11 fusion. Am. J. Hematol. 2009. © 2009 Wiley‐Liss, Inc.     

t(7;11)(p15;p15) Chronic myeloid leukaemia developed into blastic transformation showing a novel NUP98/HOXA11 fusion

We encountered a patient with Philadelphia-negative chronic myeloid leukaemia, with t(7;11)(p15;p15), in whom acute leukaemia phase (acute myeloid leukaemia-M2 morphology) developed within a short period. We detected a novel gene fusion between NUP98 and HOXA11 both in the chronic phase and in the acute leukaemia phase in this case. Although it is well known that a fusion of NUP98-HOXA9 in myeloid malignancies is created by the t(7;11)(p15;p15), this case suggests the possibility that HOXA11 might be another partner gene for NUP98 in t(7;11)(p15;p15) leukaemia.     

New Translocations in Chronic Granulocytic Leukaemia: t(X;22) (p22;q11) and t(15;22) (q26;q11)

Two cases of Ph1-positive chronic granulocytic leukaemia with hitherto undescribed translocations are presented. In case 1 the deleted part of chromosome number 22q- was translocated to the short arm of the X chromosome, t(X;22)(p22;q11). Pronounced basophilia, trisomy 19 in the majority of metaphases, and a partial cytogenetic normalization of the bone marrow during busulphan induced remission were additional remarkable features of this case. In case 2 a translocation t(15;22)(q26;q11) was found. In this case the disease was characterized by an increase of unusually small megakaryocytes, thrombocytosis, and an accelerated course.     

HRAS1 and INS genes are relocated but not structurally altered as a result of the t(7;11) (p15;p15) in a clone from a patient with acute myeloid leukaemia (M4)

A patient whose leukaemic cells carried the rare t(7;11)(p15;p15) was diagnosed as having acute myelomonocytic leukaemia (AML-M4), and supports the association of this specific translocation with forms of acute myeloid leukaemia showing differentiation. Blast phase chronic myeloid leukaemia was excluded by lack of involvement of the ABL and BCR genes. Chromosome in situ hybridization studies showed that both the HRAS1 and INS genes were present on the terminal part of chromosome 11p which was translocated to chromosome 7p. Neither HRAS1 nor INS were structurally rearranged. Field inversion gel electrophoresis showed that a 400 kb fragment encompassing HRAS1 was structurally entire in leukaemic DNA. Because the INS gene, which was also translocated, is probably located proximal to HRAS1 on chromosome 11p, it is unlikely that HRAS1 was near the chromosome 11 breakpoint or involved in this leukaemia.     

Deletion analysis of p16(INKa) and p15(INKb) in relapsed childhood acute lymphoblastic leukemia

This study aimed at determining the prevalence of INK4 deletions and their impact on outcome in 125 children with acute lymphoblastic leukemia (ALL) at first relapse using real-time quantitative polymerase chain reaction. Patients were enrolled into relapse trials ALL-REZ BFM (ALL-Relapse Berlin-Frankfurt-Münster) 90 and 96. The prevalence of p16(INK4a) and p15(INK4b) homozygous deletions was 35% (44 of 125) and 30% (38 of 125), respectively. A highly significant association of both gene deletions was found with the 2 major adverse prognostic factors known for relapsed childhood ALL: T-cell immunophenotype and first remission duration. There was no correlation between INK4 deletions and probability of event-free survival. These findings argue against an independent prognostic role of INK4 deletions in relapsed childhood ALL.     

Donor Cell-Derived Chronic Myeloproliferative Disease with t(7;11)(p15;p15) after Cord Blood Transplantation in a Patient with Philadelphia Chromosome-Positive Acute Lymphoblastic Leukemia

We report a case of donor cell-derived chronic myeloproliferative disease with t(7;11)(p15;p15) occurring after cord blood transplantation (CBT). A 41-year-old man developed precursor B-cell acute lymphoblastic leukemia with a karyotype of 46, XY, t(9;22)(q34;q11) and inv(9)(p11;q13), for which he received CBT from a sex-mismatched donor at the first complete remission of the leukemia. Five months after CBT, gradual neutrophilia of unknown origin developed following the myeloid reconstitution after CBT. Karyotyping of bone marrow cells at 9 months after CBT showed 46, XX, t(7;11)(p15;p15) in 17/20 dividing cells, but neither Philadelphia chromosome (Ph) nor inv(9)(p11;q13) was present. This is the first report of chronic myeloproliferative disease with t(7;11)(p15;p15) that developed in donor cells after CBT. The donor was well-developed and healthy, at least at the time of follow-up, half a year after the birth.     

NUP98 is fused to the NSD3 gene in acute myeloid leukemia associated with t(8;11)(p11.2;p15)

Fusion between the NUP98 and NSD3 genes in a patient with acute myeloid leukemia associated with t(8;11)(p11.2;p15), is reported for the first time. The t(8;11)(p11.2;p15) was identified by classical cytogenetics. Fluorescence in situ hybridization (FISH) analysis revealed a split signal with a mix of BAC 118H17 and 290A12, indicating the translocation disrupted NUP98. FISH restriction at 8p11-12 showed a split of BAC 350N15. Molecular investigations into candidate genes in this BAC showed the NUP98 fusion partner at 8p11.2 was the NSD3 gene. To date the NSD3 gene has never been implicated in hematologic malignancies.     

Homozygous deletions of the p15 (MTS2) and p16 (CDKN2/MTS1) genes in adult T-cell leukemia

Adult T-cell leukemia (ATL) is associated with prior infection with human T-cell leukemia virus type I (HTLV-I). Twenty to 40 years often elapse from viral infection to overt ATL, suggesting that other genetic events must occur to produce frank leukemia. The p15 (MTS2) and p16 (CDKN2/MTS1) genes located on chromosome 9p have been implicated as candidate tumor-suppressor genes in several types of tumors. We examined for alterations of these genes in ATL using Southern blot and polymerase chain reaction-single-strand conformation polymorphism analyses. Both p15 and p16 genes were homozygously deleted in 4 of 23 acute/lymphomatous ATL (17%). An additional 3 (13%) and 4 (17%) acute/lymphomatous samples had hemizygous deletions in at least one exon of p15 and p16, respectively. One of 14 chronic ATL samples had a homozygously deleted p16 gene and another had a hemizygous deletion of p16. Neither homozygous nor hemizygous deletions of the p15 gene were found in chronic ATL. In total, 10 of 37 (27%) ATL samples had loss of the p15 and/or p16 genes. No point mutations of the p15 and p16 genes were found. The ATL patient with a homozygously deleted p16 in the chronic phase rapidly progressed to acute ATL and died within 6 months of the initial diagnosis. One instructive patient had no detectable deletion of the p15 and p16 genes during the chronic phase of ATL but had a homozygous deletions of both genes when she progressed to acute ATL. Our results suggest an association of p15/p16 deletions with development of acute ATL.