Identification of the chromosome 12 translocation breakpoint region of a pleomorphic salivary gland adenoma with t(1;12)(p22;q15) as the sole cytogenetic abnormality.

Cell line Ad-312/SV40, which was derived from a primary pleomorphic salivary gland adenoma with t(1;12)(p22;q15), was used in fluorescence in situ hybridization (FISH) analysis to characterize its translocation breakpoint region on chromosome 12. Results of previous studies have indicated that the chromosome 12 breakpoint in Ad-312/SV40 is located proximally to locus D12S8 and distally to the CHOP gene. We here describe two partially overlapping yeast artificial chromosome (YAC) clones, Y4854 (500 kbp) and Y9091 (460 kbp), which we isolated in the context of a chromosome walking project with D12S8 and CHOP as starting points.

Translocation t(12;16)(q13;p11) in myxoid liposarcoma and round cell liposarcoma: molecular and cytogenetic analysis.

Translocation t(12;16)(q13;p11) is regarded as a diagnostic marker for myxoid liposarcoma. Cytogenetic data on round cell liposarcomas and combined myxoid and round cell tumors is scarce, and the genetic basis of progression of myxoid tumors to high grade, round cell lesions is unknown. We have accumulated six round cell, four combined myxoid and round cell, and three myxoid liposarcomas for analysis.

Predictive testing for Huntington's disease: risk perception, reasons for testing and psychological profile of test applicants.

In the Center for Human Genetics in Leuven, predictive DNA-testing for Huntington's disease is available as a clinical service since November 1987, initially by DNA-linkage and since mid 1993 by direct mutation analysis. The multidisciplinary approach as well as the detailed test protocol are described. The present paper gives a sociodemographic description of the test applicants, their subjective evaluation of the risk and their motives for requesting the predictive test.

Mantle cell lymphoma: a clinicopathological study of 55 cases.

A recently described unifying proposal for mantle cell lymphoma has led to the formulation of strict diagnostic criteria based on morphology, immunology and molecular data to define this specific entity. Previous studies were often based on broader definitions such as centrocytic lymphoma, intermediately differentiated lymphoma or mantle zone lymphoma and, therefore, included a variety of entities with some, but not all, features ascribed to the mantle cell lymphoma. Since the publication of the unifying proposal no comprehensive studies have been published to confirm and support it.

T-lymphoid extramedullary (lymphadenopathic) blast crisis in CML.

T-cells are only rarely involved in chronic myeloid leukemia. We report an unusual case of T-lymphoid extramedullary (lymphadenopathic) blast crisis in a 66-year-old patient with Philadelphia positive chronic myeloid leukemia. The lymph node morphological picture resembled that of a peripheral T-cell lymphoma.

A physical map of the region spanning the chromosome 12 translocation breakpoint in a mesothelioma with a t(X;12)(q22;p13).

We have constructed a physical map of a 4.6-cM region of human chromosome band 12p13.3 that contains a translocation breakpoint from a mesothelioma with a t(X;12)(q22;p13).

Fragile X boys: evolution of the mental age in childhood. Preliminary data on 10 prepubertal boys.

In this report we present data on the longitudinal evolution of the mental versus the chronological age in 10 fragile X boys diagnosed before the age of 6 years and compare these findings to the longitudinal evolution in children with Down syndrome (6 patients) and Williams syndrome (4 patients). The present findings suggest that the evolution of the velocity of development is more decreased in fra(x) boys compared to the two other groups.

Cytogenetics of hybrid acute leukemias.

Although the recognition of hybrid acute leukemia (HAL) is still controversial, several reports have described cytogenetic findings in these leukemias over the last 3 years. A distinct chromosomal profile appears to be associated with different immunologic subsets of HAL. The classical t(15;17), and inv(16) as well as abnormalities of the long arm of chromosome 5 and/or 7 are preferentially associated with acute myeloid leukemia (AML) with T-cell features; the t(8;21)(q22;q22), the Ph chromosome, and 11q23 rearrangements are more frequently found in AML with B-cell features; the Ph chromosome, t11q23 and 14q32 breaks without rearrangements of the immunoglobulin heavy chain gene may be associated with acute lymphoblastic leukemia (ALL) with myeloid markers.

New discriminative chromosomal marker in adipose tissue tumors. The chromosome 8q11-q13 region in lipoblastoma.

Specific chromosome abnormalities characterize benign and malignant adipose tissue tumors and are of great diagnostic and clinical importance. Lipoblastoma is a rare benign adipose tumor that mimics myxoid liposarcoma histologically. Although only a few lipoblastomas have been investigated cytogenetically, it is increasingly clear that these adipose tissue tumor generally show rearrangements of 8q11-q13 region but lack the t(12;16) that allows these tumors to be distinguished from myxoid liposarcomas.

A stigmatizing effect of the carrier status for cystic fibrosis?

The emotional impact of carrier detection for CF was assessed in a group of adults tested before 1992. Of the 200 adults who received a mailed questionnaire, 70% participated. One third were CF gene carriers.

Chromosome aberrations in fibrous dysplasia.

We report the cytogenetic findings of two cases of fibrous dysplasia, one occurring in the tibia, the other in the sphenoid. Both cases exhibited only one chromosome change: a t(6;11)(q15;p15) in the first case, a derivative chromosome 2 in the second. The previous cytogenetic report on fibrous dysplasia revealed only numerical changes.

Identification, molecular cloning, and characterization of the chromosome 12 breakpoint cluster region of uterine leiomyomas.

Recent molecular cytogenetic analysis of uterine leiomyoma cell lines with chromosome 12 aberrations has indicated that their chromosome 12 breakpoints map between linkage locus D12S8 and the CHOP gene. Here, we report fluorescence in situ hybridization (FISH) and molecular cloning studies of the chromosome 12 breakpoints in a panel of seven such uterine leiomyoma cell lines; five with the frequently observed t(12;14)(q15;q24), one with t(12;15)(q15;q24), and one with ins(12;11)(q14;q21qter). Directional chromosome walking studies starting from D12S8 and the CHOP gene resulted in the isolation of a relatively large number of overlapping YAC clones, including Y5355 (465 kbp), Y7673 (360 kbp), and Y9899 (275 kbp).

"Jumping" translocation of 9q in a case of follicular lymphoma.

Cytogenetic and fluorescence in situ hybridization (FISH) studies on a t(14;18)-positive follicular lymphoma presenting a remarkable pattern of secondary chromosomal changes are reported. Chromosome analysis of a lymph node biopsy performed at diagnosis revealed the presence of four related subclones characterized by the (14;18) translocation alone or together with one of the following anomalies: add(1)(p36), add(13)(q34), or der(12)(12;13)(q24;q14)add(13)(q34). The chromosome 9 origin of the extra material on the abnormal chromosomes 1 and 13 was demonstrated by FISH and points to "jumping" translocation in the present case.

Trisomy 12 in chronic lymphocytic leukemia and hairy cell leukemia: a cytogenetic and interphase cytogenetic study.

Fluorescent in situ hybridization (FISH) with a chromosome 12-specific pericentromeric probe was performed in 42 patients with B-cell chronic lymphocytic leukemia (CLL) and in 10 patients with hairy cell leukemia (HCL). In all cases, a normal karyotype in more than 10 metaphase cells was obtained by conventional chromosome study. FISH documented that 6/42 patients with CLL in fact had trisomy 12 in 15-49% interphase cells.

Cytogenetic characterization of tenosynovial giant cell tumors (nodular tenosynovitis).

Chromosome investigation in six localized forms of tenosynovial giant cell tumors, also known as modular tenosynovitis, revealed an identical translocation between chromosomes 1 and 2, t(1;2)(p11;q35-36) in three tumors, a variant translocation t(1;5)(p11;q22) in a fourth case, and a t(2;16)(q33;q24) in a fifth case. One case showed a normal karyotype. Although morphologically rather uniform, these benign tumors appear to be cytogenetically heterogeneous, but the chromosome changes seem to cluster in 2 regions, 1p11 and 16q24.

Differential expression of multiple cell-surface heparan sulfate proteoglycans during embryonic tooth development.

Heparan sulfate accumulates on cell surfaces and at cell-matrix interfaces, and functionally modulates several of the effector molecules that support the interactions, growth, and differentiation of developing tissues. Using heparin sulfate-specific monoclonal antibodies MAb, we obtained evidence that extracts from rodent embryos contain multiple forms of cell surface-associated heparan sulfate proteoglycan (PG). Taking tooth development in the mouse embryo as a model to further investigate the relevance of this PG redundancy and using MAb against heparan sulfate, antibodies specific for syndecan (syndecan-1) and fibroglycan (syndecan-2) (two distinct members of a larger family of cell-surface heparan sulfate PGs), and specific cDNA probes for these two cell-surface PGs, we obtained in situ evidence for regulated and differential expression of multiple cell-surface heparan sulfate PGs.

Adults with Williams-Beuren syndrome: evaluation of the medical, psychological and behavioral aspects.

In order to evaluate the medical, psychological and behavioral aspects of Williams-Beuren syndrome in adulthood, data were collected on 11 patients aged 17 to 66 years. The medical data did not confirm previous reports of significant morbidity. All adults were found to have a moderate or severe degree of mental handicap.

Identification of four genes coding for isoforms of murinoglobulin, the monomeric mouse alpha 2-macroglobulin: characterization of the exons coding for the bait region.

Murinoglobulins are the single chain members of the alpha 2-macroglobulin family of proteinase inhibitors in the mouse. DNA clones representing the genes coding for four different murinoglobulins were isolated from three independent mouse genomic DNA libraries. Sequence analysis demonstrated that in each gene two exons are coding for the bait region.

Molecular cloning of the mouse gene coding for alpha 2-macroglobulin and targeting of the gene in embryonic stem cells.

We have cloned the mouse gene coding for alpha 2-macroglobulin in overlapping lambda clones and have analyzed its structure. The gene contains 36 exons, coding for the 4.8-kb cDNA that we cloned previously.

Characterization of the human alpha 2-macroglobulin gene promoter: identification of a novel, triple TRE/RARE/ERE response element.

Human alpha 2-macroglobulin is synthesized in the liver and in some extra-hepatic tissues but the physiological role of the protein remains unexplained. We initiated studies to characterize the promoter of the gene. In transient transfections 240 bp of the proximal promoter were necessary and sufficient for CAT-expression in HepG2 cells and lung fibroblasts.

Trisomy 12 is uncommon in typical chronic lymphocytic leukaemias.

The incidence of trisomy 12 was studied by conventional chromosome analysis in 111 patients referred as B-cell chronic lymphocytic leukaemia (B-CLL). Fluorescent in situ hybridization (FISH) was also applied in 34 of those patients with either a normal karyotype or no analysable mitoses. By karyotyping, trisomy 12 was present in 11.

t(1;19) without detectable E2A rearrangements in two t(14;18)-positive lymphoma/leukemia cases.

Translocation t(1;19)(q23;p13) plays a crucial role in the pathogenesis of childhood pre-B cell leukemia and results in the formation of a fusion gene E2A-PBX1 that encodes a hybrid transcription factor with oncogenic potential. Here we describe two cases, one follicular lymphoma and one acute lymphoblastic leukemia/lymphoma, characterized by a complex karyotype including t(14;18), t(8;14), as well as t(1;19). Molecular studies in both cases failed to show rearrangements of the E2A gene.

Pleuropulmonary blastoma (pulmonary blastoma of childhood): genetic link with other embryonal malignancies?

A case of pleuropulmonary blastoma (childhood variant of pulmonary blastoma) was examined using histological, immunohistochemical, ultrastructural and cytogenetic methods. The tumour consisted of undifferentiated 'blastematous' areas admixed with zones of rhabdomyoblastic and chondroid differentiation and fascicular areas. Desmin and S-100 protein immunoreactivity confirmed the myogenic and cartilaginous differentiation.