Position effect in translocation (2;8) in acute lymphocytic leukemia with kappa light chain immunoglobulin expression

Acute lymphoblastic leukemia and chromosome 21

A short review of chromosome 21 abnormalities in acute lymphoblastic leukemia (ALL) is presented. Trisomy and polysomy 21 are nonrandom anomalies that are frequently observed in ALL. Their occurrence, although not specific, as well as the high incidence of acute leukemia in subjects with constitutional trisomy 21, suggests that chromosome 21 plays a particular role in leukemogenesis. More specific to ALL, t(12;21)(p13;q22), resulting in a fusion TEL-AML1, gene has recently been shown to be the most frequent translocation in childhood B-cell lineage ALL (20-30% of cases). In addition, the importance of analysis of marker chromosomes with fluorescence in situ hybridization (FISH) techniques is underscored as partial amplifications or rearrangements of chromosome 21 may be implicated.

Burkitt lymphoma with a duplication of der(8)t(2;8). Interpretation of a complex karyotype by chromosome painting

A 51-year-old male patient was diagnosed with Burkitt lymphoma 3 months after cardiac transplantation. The bone marrow karyotype was very complex, and to better define the complex karyotype we used the in situ suppression hybridization technique. Previously we interpreted this karyotype to be: 48,XY,t(2;8)(p11;q24), +der(2)t(2;8)(p11;q24),del(2)(q23), +7, +der(8)t(2;8)(p11;q24), +12, -13, -18, by G banding techniques, with a duplication of the t(2;8) derivatives. After in situ hybridization we changed to a: 48,XY,t(2;8)(p11;q24),t(2;18)(q23;q22), +7, +der(8)t(2;8)(p11;q24), +12, -13, which implies duplication of only one t(2;8) derivative.

Chromosomal abnormalities in adult non-endemic Burkitt's lymphoma and leukemia: 22 new reports and a review of 148 cases from the literature

Tumour cell karyotypes from patients with Burkitt lymphoma (BL) or Burkitt's type leukemia (ALL3) were studied for correlation with survival, bone marrow and cerebral spinal fluid involvement (CSF), human immunodeficiency virus (HIV) serology, and for recurrent cytogenetic abnormalities. The records of 22 patients with BL from our institution and of 148 cases of BL and ALL3 reported in the literature with karyotypes were evaluated for clinical and cytological features. Overall survival was only 28 per cent and 88 per cent of deaths occurred within the first nine months after diagnosis. Those who survived at least 18 months were unlikely to relapse. Age and gender did not significantly affect survival. Patients presenting with advanced Ann Arbor stage, bone marrow or CSF involvement had lower survival rates. The association of translocations involving chromosome band 8q24 with this disease is confirmed. Sixty-two per cent of karyotypes had t(8;14)(q24;q32) translocations; the recognized variant translocations t(8;22)(q24;q11) and t(2;8)(p12;q24) affected 12 per cent and 9 per cent respectively. Seventeen per cent had abnormal karyotypes but no classic translocation. Patients with variant translocations had the poorest survival rates, and those with the classic t(8;14)(q24;q32) did the best. Despite a small sample size, the variant translocation t(8;22)(q24;q11) appeared to occur at an increased frequency in the patients with AIDS. In the entire group, recurrent involvement of chromosome regions 1q2, 6q11-14 and 17p1 suggests that alteration of genes at these loci, B Cell Growth Factor (BCGF) at 1q2 and p53 on 17p, may contribute to the development and progression of this tumour. Similarly, the frequent trisomies of chromosomes 7, 8, 12 and 18 may indicate an effect on tumour cell growth due to increased gene dosage. Trisomy 12 was found in eight tumours, five from patients with AIDS, suggesting that chromosome 12 has a site or gene whose allelic dosage is selected for in AIDS related lymphoma cells. Cytogenetic studies of adult Burkitt lymphoma and leukemia suggest several likely loci for gene alterations that in conjunction with myc translocations can lead to tumorigenesis.

del(2)(p23): a new recurrent abnormality in acute myeloid leukemia

In two patients with acute myeloid leukemia, we found a new chromosome abnormality: del(2)(p23) which was detected in 13% and 50% of studied bone marrow cells, respectively. In patient one, del(2p) was an additional abnormality to t(8;21), while patient two had del(2p) as the sole abnormality. Based on our observation and a review of the literature we propose that del(2p) is a new recurrent chromosome abnormality for acute myeloid leukemia.

A variant Burkitt-type translocation (2p-;8q+) in a patient with diffuse large cell lymphoma

A case of diffuse large cell lymphoma with t(2p-;8q+) is reported. Immunologically the lymphoma cells were shown to be of B-cell origin and positive for surface gamma and kappa chains, B4, CALLA, and Ia1 markers. Karyotypically three major clones were detected: 47,XX, + 12,t(2;8)(p11-13;q24) (52%); 47,XX, + 12 (26%); and 46,XX,t(2;8)(p11-13;q24) (15%). A t(2p-;8q +) has been exclusively reported in cases of Burkitt's lymphoma or Burkitt-type acute lymphocytic leukemia. The present case is the first one with t(2p-;8q +) observed in non-Burkitt-type lymphoid malignancy of the B-cell lineage. The t(2p-;8q +) may play a primary role in the early stage of transformation of B cells, and trisomy 12 may provide them secondarily with an advantage for tumor progression. The phenotypic pictures provided by 8q24 rearrangements seem to be heterogeneous, as previously suggested.

Simultaneous presence of translocations t(14;18) and t(2;8) in a case of chronic lymphocytic leukemia

We report a patient with classical chronic lymphocytic leukemia of IgM kappa phenotype and a stable clinical course, in which repeated chromosome analyses of blood lymphocytes revealed the coexistence of t(14;18), a marker often associated with follicular low grade lymphocytic lymphomas, and t(2;8), a variant of the t(8;14) typically seen in Burkitt's lymphoma. Both these translocations involve immunoglobulin gene regions, the t(2;8) being almost always found in patients with kappa light chain restriction. However, in an EBV-immortalized cell line of this patient, most karyotypes contained t(14;18) alone, without the t(2;8). This suggests that t(14;18) was the primary cytogenetic event, and that t(2;8) evolved subsequently. As a secondary cytogenetic event, the t(2;8) may not share the grave clinical consequences of a primary t(2;8) as seen in Burkitt's lymphoma and related disorders.

Unexpected lambda chain expression in lymphocytic malignancy

Specific chromosome changes occur in the initiation and progression of cancer. A translocation between chromosomes 14 and 18 arises as a primary cytogenetic event in the formation of non-Hodgkin, non-Burkitt lymphomas (BL), while a translocation between chromosomes 2 and 8 is seen in BL and BL-type acute lymphocytic leukemia (ALL-L3) with expression of kappa (kappa) light immunoglobulin chains. These two translocations were detected in a lymphocytic malignancy expressing not kappa, but lambda (lambda) light chains. The anomalous light chain expression, it appears, provides the key clue indicating that the translocation between chromosomes 14 and 18 arose first during lymphoma formation in a cell committed to lambda chain synthesis and the translocation between chromosomes 2 and 8 occurred in the transformation to ALL. This sequence of cytogenetic events is consistent with the clinical course from lymphocytic lymphoma to ALL, the immunologic phenotype of the malignancy, and the concept of a cascade of chromosome changes eventuating in aggressive cancer.

Kappa and lambda immunoglobulin expression associated with abnormalities of chromosomes #2 and #22 in lymphoma and leukemia

The types of surface immunoglobulins on Burkitt lymphoma (BL) cells correlate with the specific chromosomes that are altered in the tumor. For example, BL with a t(2;8) translocation expresses kappa (kappa) light chains, whereas BL with a t(8;22) translocation expresses lambda (lambda) light immunoglobulin chains; these correspond with the locations of the kappa chain genes on chromosome #2 and the lambda chain genes on chromosome #22, respectively (1-5). In order to explain this close correlation between specific translocations and light chain expression in BL and BL-type acute lymphocytic leukemia (ALL) (L3 type), Hecht et al. [6] proposed the concept of position effect, which is reviewed herein.