Trisomy 4 associated with acute lymphocytic leukaemia

MLLT10 and IL3 rearrangement together with a complex four-way translocation and trisomy 4 in a patient with early T-cell precursor acute lymphoblastic leukemia: A case report

Cytogenetic classification of acute lymphoblastic leukemia (ALL) is primarily based on numerical and structural chromosomal abnormalities. In T-cell ALL (T-ALL), chromosomal rearrangements are identified in up to 70% of the patients while the remaining patients show a normal karyotype. In the present study, a 16-year-old male was diagnosed with T-precursor cell ALL and a normal karyotype after standard GTG-banding, was studied retrospectively (>10 years after diagnosis) in frame of a research project by molecular approaches. In addition to molecular cytogenetics, multiplex ligation-dependent probe amplification (MLPA) and high resolution array-comparative genomic hybridization (aCGH) were also applied. Thus, the following yet unrecognized balanced chromosomal aberrations were detected: der(3)t(3;5)(p23;q31.1), der(5)t(3;5)(p23;q35.3), der(5)t(5;10)(q31.1;p12.3) and der(10)t(5;10)(q35.3;p12.3). The oncogene MLLT10 was involved in this rearrangement as was the IL3 gene; in addition, trisomy 4 was present. All of these clonal aberrations were found in 40% of the cells. Even if this complex karyotype would have been identified at the time of diagnosis, most likely no other protocol of anticancer therapy (ALL-BFM 95) would have been applied. Three months after the end of a successful 2-year treatment, the patient suffered from isolated bone marrow relapse and died of sepsis during ALL-REZ-BFM protocol treatment.

Trisomy 4 as the sole cytogenetic abnormality in a patient with T-cell acute lymphoblastic leukemia

Trisomies as sole cytogenetic abnormalities are extremely rare in acute lymphoblastic leukemia (ALL). We describe here the clinical features and immunophenotyping, cytogenetic, and fluorescence in situ hybridization (FISH) findings in a T-cell ALL patient with trisomy 4 as the sole cytogenetic abnormality. The leukemic clone was positive for CD2, CD7, CD34, and terminal deoxynucleotidyl transferase (TdT); CD13 was weakly expressed. Data on the tracking of the leukemic clone with immunophenotyping, cytogenetic, and FISH studies are discussed. The present case is compared with the three previous reported cases of trisomy 4 in ALL. Due to the rarity of this cytogenetic abnormality, its prognostic significance in ALL remains unclear.

Is trisomy 4 a secondary chromosomal abnormality in acute myeloblastic leukemia?

Cytogenetic studies were carried out in a patient with acute monocytic leukemia (AML-M5) at diagnosis and in relapse. While no chromosome abnormality was detected initially, isolated trisomy 4 was found in relapse. The primary or secondary nature of trisomy 4 as the sole abnormality in AML is discussed.

Biphenotypic M0 acute myeloid leukemia with trisomy-4

We report here a rare case of biphenotypic M0 acute myeloid leukemia (AML) associated with trisomy 4. The literature of trisomy 4 in acute leukemia was reviewed. M2 and M4 AML are the most common FAB subtypes associated with trisomy 4. The clinical course of this entity is generally comparable with other non-trisomy 4 cases of AML. Despite the speculation made when first described, no specific environmental toxin has been found to be associated with this entity. C-kit oncogene has been mapped to chromosome 4 recently, and the role of this proto-oncogene in leukemogenesis of trisomy 4 associated leukemia should be further investigated.

Overexpression of c-kit in a leukemic cell population carrying a trisomy 4 and its relationship with the proliferative capacity

The expression of c-kit and its ligand, the stem cell factor (SCF), was studied in five cases of acute myeloid leukemia. One of these had a trisomy of chromosome 4, where the c-kit oncogene is located. In this case, the c-kit oncogene was overexpressed, but matched by a low expression of its ligand, SCF. The molecular evaluation of the growth rate by c-myc and the histone H3 expression indicated that the growth fraction of this cell population was very low. In one of the other leukemic cell populations studied, characterized by a low expression of c-kit and an elevated expression of the SCF, the growth fraction was also very low. Our results suggest that at least for some receptor oncogenes, the simple overexpression cannot be taken as an indication that the oncogene is involved in the deregulation of cell proliferation.

Trisomy 4 in acute myeloblastic and acute lymphoblastic leukemia

We report three cases of trisomy 4 in acute leukemia. This alteration was detected as the sole cytogenetic abnormality in a case of FAB M4 leukemia; it occurred in association with 5q deletion in a case of M1, and concomitant with Ph chromosome and trisomy 17 in a case of L2 leukemia. The latter case represents the fourth report of trisomy 4 in acute lymphoblastic leukemia.