Leukemia with a novel 4q11q rearrangement

Insertion of chromosome 11 in chromosome 4 resulting in a 5'MLL-3'AF4 fusion gene in a case of adult acute lymphoblastic leukemia

We report on a 69-year-old woman with B-lineage acute lymphoblastic leukemia. Cytogenetic studies at diagnosis with R banding showed an insertion, ins(4;11)(q21;q13q23). Fluorescence in situ hybridization (FISH) with whole chromosome painting probes confirmed the insertion of chromosome 11 material into chromosome 4. FISH using the MLL probe showed the translocation of the 5' end of MLL into chromosome 4. Since the 5'MLL-3'AF4 fusion transcript was detected by a reverse transcriptase polymerase chain reaction, we concluded that the insertion of part of chromosome 11 split the AF4 gene in two, resulting in the presence of the 5'MLL-3'AF4 fusion gene on the der(4) instead of the der(11), as commonly observed. Our findings stress the value of combining banding cytogenetics with FISH and molecular techniques to better assess rearrangements in leukemia.

Molecular analysis of an unusual rearrangement between chromosomes 4 and 11 in adult pre-B-cell acute lymphoblastic leukemia

The reciprocal t(4;11)(q21;q23) is often described in acute lymphoblastic leukemia (ALL). In some cases, variant or complex t(4;11) has been detected in ALL by cytogenetic analysis, but to our knowledge no molecular study has been reported in these variant translocations. We describe a 27-year-old woman suffering from pre-B-cell ALL with an unusual rearrangement between chromosomes 4 and 11. Because this complex rearrangement involved the 11q23 chromosome band known to be associated with poor prognosis, we performed fluorescence in situ hybridization, Southern blot, and reverse transcription polymerase chain reaction analyses. This confirmed myeloid lymphoid leukemia gene rearrangement and showed the presence of MLL/AF4 fusion transcript. These results showed the importance of molecular analysis that allowed minimal residual disease monitoring in this patient.

Acute leukemias with the t(4;11)(q21;q23)

The t(4;11)(q21;q23) has been associated with marked lineage heterogeneity. Most of the reported cases were classified as acute lymphoblastic leukemia (ALL). The t(4;11) is one of the commonest specific chromosomal translocations in ALL, occurring in 2% of childhood and 5% of adult cases. In childhood ALL, this translocation is associated with female sex, age less than 1 year, hyperleukocytosis, CD10-/CD19+ B-precursor cell immunophenotype, and myeloid-associated antigen (CD15) expression. There also appears to be an age-related difference in treatment outcome. Adults had the worst prognosis, and children aged 1 to 9 years appeared to have a better outcome than infants or adolescents. Reported cases of acute myeloid leukemia (AML) or secondary leukemia with the t(4;11) have not been well characterized. It is intriguing that virtually all of the reported cases with secondary leukemia had received epipodophyllotoxins or doxorubicin, agents that affect topoisomerase II and are associated with secondary AML characterized by 11q23 abnormalities. Identification of the involved gene(s) in the t(4;11) will provide a molecular approach permitting more accurate classification of these cases.

Investigation of the CD10 (cALLA) negative acute lymphoblastic leukaemia: further description of a group with a poor prognosis. French Groupe d'Etude Immunologique des Leucémies

The absence of CD10 (cALLA) in non-T non-B acute lymphoblastic leukaemia (ALL) is usually considered to be of adverse prognostic significance. From a large multicentre series of phenotyped ALL, we have identified a group of 23 non-T non-B ALL where blast cells were CD10 negative and CD19 positive. Class II antigens were present in 80% and C19 in 70%. Eight patients had successful karyotype analysis at diagnosis, and an additional patient at first relapse. Seven of these karyotypes showed a (4;11) (q21;q23) translocation. Most of the patients (70%) were young females, and they often presented with organomegaly. Six patients were less than 1 year old. The white cell count was over 100 x 10(9)/l in 48% of the cases. The FAB type was L2 in 56% of the patients. The most striking features were the poor response to therapy and survival. Six patients never attained complete remission and nine patients relapsed, most of them during the first year after diagnosis. Allogeneic bone marrow transplantation was performed in three children, of whom two are still alive 2 years after diagnosis. This study emphasizes the prognostic value of immuno-phenotypic and karyotypic investigations of ALL.

A translocation t(9;11)(p11;q23) in T-cell acute lymphoblastic leukemia (FAB-l2)

We here report a t(9;11)(p11;q23) as the only abnormality in the affected cells of a 20-year-old male with acute lymphoblastic leukemia (L2) of T-cell origin. One hundred six patients with acute leukemia and involvement of band 11q23 were reviewed. Young age, hyperleukocytosis, and poor prognosis characterized almost all the cases in the acute leukemias with the 11q23 translocation, despite involvement of different recipient chromosomes and different morphologic and immunologic phenotypes.

Unusual cytogenetic findings in two patients with t(4;11) acute leukemia

Unusual cytogenetic findings are described in two patients with acute leukemia and rearrangements involving chromosomes 4 and 11. Both patients had clinical and phenotypic features often found in leukemia with t(4;11)(q21;q23). At initial diagnosis, one patient showed a standard t(4;11) with duplication of the 4q-translocation derivative. The latter finding has been described previously in a few patients with t(4;11) in association with disease progression. By analogy with the Ph1 chromosome in chronic myelogenous leukemia, duplication of the 4q-suggests that this derivative is the critical recombinant in the t(4;11). The second patient has a novel complex translocation, t(4;11;15)(q21;q23;q21). Analysis of this variant translocation implies that the 11q+ is the consistent chromosome rearrangement in this type of leukemia. The apparent contradiction of the findings in these and other relevant reported cases reviewed here suggests that genes on both the 11q+ and 4q- recombinant chromosomes are important, in either the etiology or the progression of this disease.