Translocation t(14;18) in B cell lymphomas as a cause for defective immunoglobulin production.

Although follicle center cell (FCC) lymphomas represent mature B cells, a considerable percentage do not have detectable Ig production. We have used Southern blotting and the polymerase chain reaction (PCR) to study the involvement of translocations t(14;18) and t(8;14) in causing defective Ig production in 16 Ig- FCC-derived lymphomas and three Ig- B cell acute lymphoblastic leukemias. In 6 of 19 cases, a t(14;18) was present with the other allele either deleted or in germline. In two cases a t(14;18) and a t(8;14) affected both Ig alleles, as confirmed by karyotyping. In two other cases, rearrangement of both bcl-2 on chromosome 18 and c-myc on chromosome 8 were found as well. Although cytogenetic proof was not available, the latter was probably involved in t(8;14). Restriction map analysis of one more case showed rearrangement on the pseudo-JH3 gene on one allele and t(14;18) on the other. Thus, in 11 of 19 cases, defective Ig H chain production could be explained by the inactivation of both Ig H chain genes due to translocation of one allele, in combination with deletions or defective rearrangements of the other allele. In contrast, in 28 of 30 Ig+ lymphomas, one functional Ig H chain allele was found, either in, or not in, combination with t(14;18). In two cases a single rearranged Ig H chain allele was found in combination with rearrangement of bcl-2. No comigration of the single Ig rearrangement with bcl-2, however, was found both by Southern blotting and PCR, suggesting a variant bcl-2 translocation, which leaves the Ig H chain allele functionally intact.

Genomic acute myeloid leukemia-associated inv(16)(p13q22) breakpoints are tightly clustered.

The inv(16) and related t(16;16) are found in 10% of all cases with de novo acute myeloid leukemia. In these rearrangements the core binding factor beta (CBFB) gene on 16q22 is fused to the smooth muscle myosin heavy chain gene (MYH11) on 16p13. To gain insight into the mechanisms causing the inv(16) we have analysed 24 genomic CBFB-MYH11 breakpoints. All breakpoints in CBFB are located in a 15-Kb intron. More than 50% of the sequenced 6.2 Kb of this intron consists of human repetitive elements. Twenty-one of the 24 breakpoints in MYH11 are located in a 370-bp intron. The remaining three breakpoints in MYH11 are located more upstream. The localization of three breakpoints adjacent to a V(D)J recombinase signal sequence in MYH11 suggests a V(D)J recombinase-mediated rearrangement in these cases. V(D)J recombinase-associated characteristics (small nucleotide deletions and insertions of random nucleotides) were detected in six other cases. CBFB and MYH11 duplications were detected in four of six cases tested.

Mosaicism of the 5q deletion as assessed by interphase FISH is a common phenomenon in MDS and restricted to myeloid cells.

Interstitial deletion of chromosome 5q is a common cytogenetic abnormality observed in MDS. We have used fluorescence in situ hybridization (FISH) to determine accurately the percentage of cytogenetically abnormal peripheral blood cells. YAC and cosmid probes localized to chromosome 5q were hybridized to interphase nuclei from purified polymorphonuclear cells (PMNs) from six MDS patients with chromosome 5 deletions. Per patient, 25-67% of the cells exhibited one signal for the 5q31-q33 specific probes IL-4, D5S207 and c-fms. This percentage was constant for the various probes utilized for each patient. Hybridization of the same probes to PMNs from healthy individuals and hybridization of probes (D5S39 and D5S498) localized outside the deleted segments to PMNs of the patients, resulted in 90-95% nuclei with two signals. In addition, FACS-purified peripheral blood cells were investigated by FISH using the IL-4 cosmid. This demonstrated that the hybridization pattern in monocytes was similar to that observed in PMNs, whereas T-lymphocytes showed no loss of signals. These results indicate that a subfraction of the myeloid progenitor cells have acquired the 5q deletion.

A new non-Hodgkin's B-cell line (DoHH2) with a chromosomal translocation t(14;18)(q32;q21).

A spontaneously growing EBV-negative B-cell line (DoHH2) was established from the pleural fluid cells of a 60-year-old man with centroblastic/centrocytic non-Hodgkin's lymphoma, that had transformed into an immunoblastic lymphoma. The pleural fluid cells and the DoHH2 cells expressed IgG lambda, were reactive with CD10 and CD19 monoclonal antibodies, and showed by cytogenetic analysis 48,XY, +7, +del(12)(q24), t(14;18)(q32;q21). Southern blot analysis of mini-satellite DNA patterns, and of rearrangements of the immunoglobulin genes and bcl-2, confirmed that the cell line was derived from the patient's clonal lymphoma cells. Direct nucleotide sequence analysis on polymerase chain reaction (PCR) products of the t(14;18) junction revealed an identical sequence for the JH-bcl-2 junction at JH6 and in the major breakpoint region of bcl-2 in both the original tumor cells and the DoHH2 cell line. The cell line was valuable as a standard quantification control for PCR analysis of the t(14;18) breakpoint. Titration experiments demonstrated the detection of up to one tumor cell in 10(5) normal blood lymphocytes.

De novo acute B-cell leukemia with translocation t(14;18): an entity with a poor prognosis.

Three cases of de novo acute B-cell lymphoblastic leukemia are presented, all with an unusual phenotype, involvement of translocation t(14;18) and additional chromosomal abnormalities, including translocation t(8;14) and deletion of chromosome 9. In contrast to normal FAB-L2 or FAB-L3 acute lymphoblastic leukemia (ALL), these leukemias did not express cytoplasmatic and membranous immunoglobulin. The combination of translocation t(14;18) and additional chromosomal events on the other chromosome 14 account for the lack of immunoglobulin expression. In one case a low grade follicular lymphoma was found next to a high grade Burkitt type ALL. The translocation t(14;18) takes place as a mistake in the VDJH joining in pre-B cells in the bone marrow. It is proposed that some cases of de novo ALL may arise as a blast crisis induced by genetic events, secondary to the primary t(14;18) translocation. This type of ALL seems to have a poor prognosis.

Simple method for detection of MYH11 DNA rearrangements in patients with inv(16)(p13q22) and acute myeloid leukemia.

The pericentric inversion on chromosome 16 [inv(16)(p13q22)] and related t(16;16)(p13;q22) are recurrent aberrations associated with acute myeloid leukemia (AML) M4 Eo. Both abberations result in a fusion of the core binding factor beta (CBFB) and smooth muscle myosin heavy chain gene (MYH11). A selected genomic 6.9-kb BamHl probe detects MYH11 DNA rearrangements in 18 of 19 inv(16)/t(16;16) patients tested using HindIII digested DNA. The rearranged fragments were not detectable after remission in two cases tested, while they were present after relapse in one of these two cases tested.

Detection of CBP rearrangements in acute myelogenous leukemia with t(8;16).

The CREB-binding protein (CBP) is a large nuclear protein that regulates many signal transduction pathways and is involved in chromatin-mediated transcription. The translocation t(8;16)(p11;p13.3) consistently disrupts two genes: the CBP gene on chromosome band 16p13.3 and the MOZ gene on chromosome band 8p11. Although a fusion of these two genes as a result of the translocation is expected, attempts at detecting the fusion transcript by reverse transcriptase polymerase chain reaction (RT-PCR) have proven difficult; to date, only one in-frame CBP/MOZ fusion transcript has been reported. We therefore sought other reliable means of detecting CBP rearrangements. We applied fluorescence in situ hybridization (FISH) and Southern blot analyses to a series of AML patients with a t(8;16) and detected DNA rearrangements of both the CBP and the MOZ loci in all cases tested. All six cases examined for CBP rearrangements have breakpoints within a 13 kb breakpoint cluster region at the 5' end of the CBP gene. Additionally, we used a MOZ cDNA probe to construct a surrounding cosmid contig and detect DNA rearrangements in three t(8;16) cases, all of which display rearrangements within a 6 kb genomic fragment of the MOZ gene. We have thus developed a series of cosmid probes that consistently detect the disruption of the CBP gene in t(8;16) patients. These clones could potentially be used to screen other cancer-associated or congenital translocations involving chromosome band 16p13.3 as well.

Hairy cell leukemia: in-vitro proliferation and pseudo-colony formation.

In an established double layer clonogenic assay, the PHA-leukocyte feeder colony assay, hairy cell leukemia (HCL) cells formed strong aggregates simulating colonies. After irradiation with 50 Gy, colony formation persisted. Even in a modified colony assay consisting of agar 0.5% overlayered by methylcellulose 0.9%, cell aggregation was still possible due to increasing fluidity of the methylcellulose during the culture period. Time-lapse video recordings confirmed prominent cell motility leading to pseudo-colony formation. Studies with bromodeoxyuridine incorporation showed a low proliferation index (up to 13%) of hairy cells. In conclusion, any assay that facilitates cell motility is unsuitable to study HCL colony growth.

A patient with dup(10p)del(8q) and Pendred syndrome.

We report on a severely retarded girl with multiple congenital anomalies. Chromosome studies showed a der (8) chromosome with dup(10p) and deficiency for a small distal segment of 8q. Her father proved to be carrier of a de novo balanced translocation between chromosome 8q and 10p. At 1 year the patient was also found to have the Pendred syndrome, an autosomal recessive defect in thyroid organification. The concurrence of chromosome anomalies and single gene disorders might not be too rare, but can be easily overlooked. Yet there are important consequences for genetic counseling. Moreover, recognition of these concurrences may help gene mapping.

Trisomy 13 and myelodysplastic syndrome.

The clinical and cytogenetic data of a patient with myelodysplastic syndrome-refractory anemia with excess blasts (MDS-RAEB) and trisomy 13 as the sole abnormality are presented. This appears to be only the second report of such a patient. The presence of trisomy 13 is confirmed by in situ hybridization using an alphoid repeat probe L1.26, which is specific for the centromeres of both chromosomes 13 and 21.

A second case of hexasomy 8 in myelodysplastic syndrome.

Tetrasomy 8 is a rare form of acquired aneuploidy found exclusively in the myeloid leukemias. Hexasomy 8 is even rarer: only one case has been reported, thus far. We describe here the second case of hexasomy 8 as the sole abnormality in an elderly female patient with myelodysplastic syndrome (MDS).

Nasopharyngeal teratoma and mosaic tetrasomy 1q detected at amniocentesis. A case report and review of the literature.

The occurrence of nasopharyngeal teratomas (NPT) is an infrequent event and prenatal detection of such tumors is even rarer. We present a case report and review of the literature (N = 78 cases), in which we describe the cytogenetic, DNA, and pathological findings of a fetus with a mature NPT which was detected prenatally by ultrasound investigation following complaints of severe polyhydramnios by the mother.

der(1)t(1;9): a specific chromosome abnormality in polycythemia vera? Cytogenetic and in situ hybridization studies.

Two patients with polycythemia vera and an extra der(1)t(1;9) chromosome are reported. In one patient this was found as the sole abnormality. The other patient originally presented with trisomy 9 but later developed an extra der(1) during the further course of the disease with disapperance of the extra chromosome 9. In situ hybridization studies on this latter patient proved that the centromere of chromosome 1 was involved in the formation of the derivative chromosome.

A case of isodicentric 7p as sole abnormality in a patient with acute myeloid leukemia.

The detection of isochromosomes in the leukemias and in solid tumors has been well described in the literature, the most common being the i(17q), which is found in the blast crisis of CML and terminal stages of acute myeloid leukemia. Reports of isochromosome 7 have, however, been less well represented, particularly isochromosomes of the short arm of chromosome 7, which represent approximately 1% of all reported isochromosomes in neoplasia. We present here a case report of an elderly female patient with AML-M2 who manifested an idic(7p) in the majority of her bone marrow cells. Fluorescence in situ hybridization (FISH) studies with both centromere-7--and chromosome-7--specific DNA probes verified the diagnosis of idic(7p). To the best of our knowledge, this is the first report of this type of leukemia with an acquired idic(7p) as the sole cytogenetic abnormality.

t(5;12)(q31;p12). A clinical entity with features of both myeloid leukemia and chronic myelomonocytic leukemia.

We report two patients with a myeloproliferative disorder (Philadelphia chromosome-negative chronic myeloid leukemia) and t(5;12)(q31;p12). Until now, only three cases of a translocation (5;12)(q31;p12) have been reported. All investigators had problems classifying their patient's disease into one of the well-defined entities of either MPD or myelodysplastic disorders. We postulate that this translocation may represent a subgroup of patients with features of both chronic myeloid leukemia and chronic myelomonocytic leukemia (CMMoL).

Characterization of a New Human B Cell Line (Bonna-12) with Trisomy 9 and Trisomy 12 Chromosomal Abnormality.

A new EBV positive human B-cell line, BONNA-12 was established from splenic cells of a patient with a hairy cell leukemia (HCL). BONNA-12 cells grew spontaneously and formed colonies in semisolid media. Although the BONNA-12 cell line was identical with the patient's spleen cells by HLA analysis and Southern blot examination of minisatellite DNA patterns, the immunoglobulin heavy and light chain rearrangement patterns differed from the original HCL. Cytogenetic analysis of the BONNA-12 cell line demonstrated in the major cell clone a 47, X, -Y, +9, +12 karyotype. Trisomy 12 is a characteristic abnormality in chronic lymphocytic leukemia that also rarely occurs in HCL. The BONNA-12 cell line is of potential value in the study of trisomy 12 in chronic B cell malignancies.

Premature menopause because of an inherited deletion in the long arm of the X-chromosome.

A family is described in which both a mother and an infertile daughter had premature menopause at the ages of 31 and 28 years, respectively. Initially, an extensive investigation revealed no apparent cause for their conditions. However, when cytogenetic analysis in the daughter was performed, a terminal deletion in the long arm of one of the X-chromosomes was found. The karyotype was: 46,Xdel(X),(q25-qter). Chromosomal investigation in the mother showed an identical deletion. The karyotype of the patient's 35-year-old sister is normal. She has a normal menstrual cycle and two normal children. The presence of such familial cases suggests that chromosomal investigation should be considered in young women with oligomenorrhea, especially those whose mothers have experienced a premature menopause.

Study on the variation in X-ray sensitivity of human diploid skin fibroblasts. Normal radiosensitivity of cells derived from patients with Huntington's disease.

9 cell strains derived from patients with Huntington's disease and 9 from age- and sex-matched controls were investigated for X-ray sensitivity. No differences in radiosensitivity were observed for the two groups. The two groups taken together reveal a dependence of radiosensitivity on intrinsic cloning efficiency which in turn correlates with donor age. A difference in radiosensitivity between males and females is also indicated although at the borderline of significance. As a parameter for radiosensitivity the dose needed to obtain 0.1% survival appears superior to the Do.

[Chimerism pattern following allogeneic bone marrow transplantation; a retrospective study of the connection with post-transplantation complications]. / Chimerismepatroon na allogene beenmergtransplantatie; een retrospectief onderzoek naar het verband met complicaties na transplantatie.

Allogeneic bone marrow transplantation is generally followed by disappearance of all host haematopoietic cells and replacement by donor cells, resulting in complete chimerism. In some cases, however, residual host cells can be detected after transplantation; this is called partial chimerism. We have analysed the chimerism pattern in 106 patients, by erythrocyte antigen typing, erythrocyte and leucocyte isoenzymes, immunoglobulin allotyping and karyotyping of bone marrow and blood. Recipients of a T cell-depleted marrow transplant exhibited partial chimerism significantly more often. In most cases this involved T lymphocytes, sometimes in combination with other cell populations. Persisting B lymphocytes of host origin were detected only in recipients of a T cell-depleted marrow graft. No relationship was found between chimerism pattern and GVHD, interstitial pneumonitis, relapse of the underlying disease or disease free survival.

[Prenatal fetal blood group determination using chorionic villi biopsy]. / Prenatale foetale-bloedgroepbepaling met behulp van chorionvilli-biopsie.

The presence or absence of Rhesus D, c and Kell antigens on foetal red blood cells was determined in the first trimester of pregnancy on erythrocytes obtained by chorionic villi sampling. Pregnancies in 15 severely sensitized women (9 Rh D, 5 Kell and I Rh c) with a poor obstetric history and a partner heterozygous for the offending antigen were examined. A conclusive diagnosis could be made in 13 of the 15 cases studied.