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PubMedDate not supplied

Balanced complex chromosomal rearrangements (BCCR) with at least three chromosomes and three or more breakpoints: report of three new cases.

Balanced complex chromosomal rearrangements (BCCR) encompass a heterogeneous group of rare chromosomal aberrations. In this paper, we report three cases of BCCRs. In two the probands were referred for either genetic counseling or prenatal management. One case was ascertained after chromosome analysis performed because of psychiatric manifestations; this was an isolated finding. We also outline the molecular cytogenetic techniques, which were essential in confirming and precisely delineating the BCCRs identified in these patients. In addition the various aspects of genetic counseling for this type of chromosomal rearrangement, highlighting the details particular to each individual case are discussed. We discuss the classification for this type of chromosomal mutation.

Abnormalities, Multiple↗
PubMed2004

Human artificial chromosomes containing chromosome 17 alphoid DNA maintain an active centromere in murine cells but are not stable.

Human artificial chromosomes (HACs) are autonomous molecules that can function and segregate as normal chromosomes in human cells. De novo HACs have successfully been used as gene expression vectors to complement genetic deficiencies in human cultured cells. HACs now offer the possibility of studying the regulation and expression of large genes in a variety of cell types from different tissues and correcting gene deficiencies caused by human inherited diseases. Complementary gene expression studies in mice, especially in mouse models of human genetic diseases, are also important in determining if large human transgenes can be expressed appropriately from artificial chromosomes. Toward this aim we are establishing artificial chromosomes in murine cells as novel gene expression vectors. Initially we transferred HAC vectors into murine cells, but were unable to generate de novo HACs at a reasonable frequency. We then transferred HACs previously established in human HT1080 cells to three different murine cell types by microcell fusion, followed by positive selection. We observed that the HACs in murine cells bound centromere protein C (CENP-C), a marker of active centromeres, and were detected under selection but rapidly lost when selection was removed. These results suggest that the HACs maintain at least a partially functional centromere complex in murine cells, but other factors are required for stability and segregation. Artificial chromosomes containing mouse centromeric sequences may be required for better stability and maintenance in murine cells.

Animals↗
PubMed1989

Familial XX chromosomal maleness does not arise from a Y chromosomal translocation.

To determine the mechanism for the coexistence of XX chromosomal maleness and true hermaphroditism in the same family, we performed cytogenetic and molecular genetic analyses, using DNA probes from the short arm of the Y chromosome. These studies excluded the following possible mechanisms: (1) an inherited, mitotically unstable Y chromosome that results in chromosomal mosaicism, (2) an inherited Y-to-X or Y-autosomal translocation, (3) recurrent Y-to-X translocation, and (4) incomplete inactivation of the X chromosomal homolog for the testicular determining factor. We conclude that the disorder of sexual differentiation observed in this family can be best explained by a dominant autosomal gene with variable expressivity.

Blotting, Southern↗
PubMed2006

Renal mucinous tubular and spindle carcinoma lacks the gains of chromosomes 7 and 17 and losses of chromosome Y that are prevalent in papillary renal cell carcinoma.

Mucinous tubular and spindle cell carcinoma of the kidney is an uncommon, distinctive neoplasm characterized by the proliferation of cuboidal and spindle cells arranged in tubular or sheet-like arrays, typically with a mucinous or myxoid background. The most important differential diagnostic consideration of mucinous tubular and spindle cell carcinoma is papillary renal cell carcinoma, type 1, with sarcomatoid transformation. The aim of our study is to investigate the pattern of possible gains or losses of chromosomes 7, 17 and Y in 10 mucinous tubular and spindle cell carcinomas with interphase fluorescence in situ hybridization (FISH). Four-micron sections were obtained from paraffin blocks representative of the tumors and including adjacent non-neoplastic renal parenchyma from 10 patients. The patients' ages ranged from 20 to 80 years (mean: 62 years); eight were female, while two were male. FISH analysis was performed with centromeric probes for chromosomes 7, 17 and Y. One hundred fifty to 200 nuclei from each case were scored for hybridization signals and non-neoplastic parenchyma served as control tissue. We found that renal mucinous tubular and spindle carcinoma lacks the gains of chromosomes 7 and 17 and losses of chromosome Y that are typical of papillary renal cell carcinoma. FISH analysis with centromeric probes for these chromosomes is potentially helpful in differentiating mucinous tubular and spindle cell carcinomas from papillary renal cell carcinomas.

Adenocarcinoma, Mucinous↗
PubMed2002

A genome screen of 13 bipolar affective disorder pedigrees provides evidence for susceptibility loci on chromosome 3 as well as chromosomes 9, 13 and 19.

Bipolar affective disorder is a severe mood disorder that afflicts approximately 1% of the population worldwide. Twin and adoption studies have indicated that genetic factors contribute to the disorder and while many chromosomal regions have been implicated, no susceptibility genes have been identified. We undertook a combined analysis of 10 cM genome screen data from a single large bipolar affective disorder pedigree, for which we have previously reported linkage to chromosome 13q14 (Badenhop et al, 2001) and 12 pedigrees independently screened using the same 400 microsatellite markers. This 13-pedigree cohort consisted of 231 individuals, including 69 affected members. Two-point LOD score analysis was carried out under heterogeneity for three diagnostic and four genetic models. Non-parametric multipoint analysis was carried out on regions of interest. Two-point heterogeneity LOD scores (HLODs) greater than 1.5 were obtained for 11 markers across the genome, with HLODs greater than 2.0 obtained for four of these markers. The strongest evidence for linkage was at 3q25-26 with a genome-wide maximum score of 2.49 at D3S1279. Six markers across a 50 cM region at 3q25-26 gave HLODs greater than 1.5, with three of these markers producing scores greater than 2.0. Multipoint analysis indicated a 20 cM peak between markers D3S1569 and D3S1614 with a maximum NPL of 2.8 (P= 0.004). Three other chromosomal regions yielded evidence for linkage: 9q31-q33, 13q14 and 19q12-q13. The regions on chromosomes 3q and 13q have previously been implicated in other bipolar and schizophrenia studies. In addition, several individual pedigrees gave LOD scores greater than 1.5 for previously reported bipolar susceptibility loci on chromosomes 18p11, 18q12, 22q11 and 8p22-23.

Bipolar Disorder↗
PubMed2002

A genome screen of 13 bipolar affective disorder pedigrees provides evidence for susceptibility loci on chromosome 3 as well as chromosomes 9, 13 and 19.

Bipolar affective disorder is a severe mood disorder that afflicts approximately 1% of the population worldwide. Twin and adoption studies have indicated that genetic factors contribute to the disorder and while many chromosomal regions have been implicated, no susceptibility genes have been identified. We undertook a combined analysis of 10 cM genome screen data from a single large bipolar affective disorder pedigree, for which we have previously reported linkage to chromosome 13q14 (Badenhop et al, 2001) and 12 pedigrees independently screened using the same 400 microsatellite markers. This 13 pedigree cohort consisted of 231 individuals, including 69 affected members. Two-point LOD score analysis was carried out under heterogeneity for three diagnostic and four genetic models. Non-parametric multipoint analysis was carried out on regions of interest. Two-point heterogeneity LOD scores (HLODs) greater than 1.5 were obtained for 11 markers across the genome, with HLODs greater than 2.0 obtained for four of these markers. The strongest evidence for linkage was at 3q25-26 with a genome-wide maximum score of 2.49 at D3S1279. Six markers across a 50 cM region at 3q25-26 gave HLODs greater than 1.5, with three of these markers producing scores greater than 2.0. Multipoint analysis indicated a 20 cM peak between markers D3S1569 and D3S1614 with a maximum NPL of 2.8 (P = 0.004). Three other chromosomal regions yielded evidence for linkage: 9q31-q33, 13q14 and 19q12-q13. The regions on chromosomes 3q and 13q have previously been implicated in other bipolar and schizophrenia studies. In addition, several individual pedigrees gave LOD scores greater than 1.5 for previously reported bipolar susceptibility loci on chromosomes 18p11, 18q12, 22q11 and 8p22-23.

Bipolar Disorder↗
PubMed1989

Clustering of breakpoints on chromosome 10 in acute T-cell leukemias with the t(10;14) chromosome translocation.

The T-cell receptor (TCR) alpha/delta chain locus on chromosome 14q11 is nonrandomly involved in translocations and inversions in human T-cell neoplasms. We have analyzed three acute T-lymphoblastic leukemia samples carrying a t(10;14)(q24;q11) chromosome translocation by means of somatic cell hybrids and molecular cloning. In all cases studied the translocation splits the TCR delta chain locus. Somatic cell hybrids containing the human 10q+ chromosome resulting from the translocation retain the human terminal deoxynucleotidyltransferase gene mapped at 10q23-q24 and the diversity and joining, D delta 2-J delta 1, regions of the TCR delta chain, but not the V alpha region (variable region of the TCR alpha chain), demonstrating that the split occurred within the V alpha-D delta 2 region. Molecular cloning of the breakpoint junctions revealed that the TCR delta chain sequences involved are made from the D delta 2 segment. The chromosome breakpoints are clustered within a region of approximately 263 base pairs of chromosome 10. The results suggest that the translocation of the TCR delta chain locus to a locus on 10q, which we have designated TCL3, results in deregulation of this putative oncogene, leading to acute T-cell leukemia.

Base Sequence↗
PubMed1976

A new chromosome deletion syndrome. Report of a patient with a 46,XY,8p- chromosome constitution.

A mentally retarded boy with narrow cranium, high forehead, epicanthic folds, flat nasal bridge, low-set but normal ears, retrognathy, short neck and broad chest with wide-set nipples is described. The routine chromosome and banding analyses revealed a 46,XY,8p- chromosome constitution. The parents had normal chromosomes. On the basis of measurements on reflectodensitometer tracings and of measurements of the individual G-bands directly on photographic prints of the normal and abnormal chromosome 8, an intercalary deletion of band p22 seemed most probable. The clinical features of the patient are compared with the 8p- case of Lubs & Lubs (1973) as well as with four other cases of short arm deletion of an unidentified C-autosome. The clinical features of one of these cases were very similar to those of the boy described. An attempt was made to delineate the clinical characteristics of this new chromosomal deletion syndrome.

Child↗
PubMed1979

Turner's syndrome with a duplication-deficiency X chromosome derived from a maternal pericentric inversion X chromosome.

A 31-year-old woman of short stature with severe oligomenorrhea was found to carry a duplication-deficiency X chromosome, 46,X,rec(X)dup q,inv(X)(p22q11), inherited from her mother who carried a pericentric inversion X chromosome, 46,X,inv(X)(p22q11). By a combination of autoradiography and BUdR incorporation, the duplication-deficiency X chromosome was always found to be the inactive and late replicating one. In the cultured fibroblasts with the recombinant X chromosome, some of the cells were seen to have bipartite X chromatin bodies. In the mother with inv(X), the normal and the inverted X chromosome were inactivated at random.

Adult↗
PubMed1988

N-ras-like sequences on chromosomes 9, 6 and 22 with a polymorphism at the chromosome 9 locus.

Two clones, pCN1 and pCN2, which together form full-length cDNA for N-ras, were used to search for restriction fragment length polymorphisms. pCN2, which entirely consists of 3' non-translated sequences, revealed more bands on DNA transfer hybridizations than could be accounted for using the known restriction map of N-ras. None of the extra cross hybridizing sequences is located on chromosome 1. One of these sequences showed a high-frequency two-allele polymorphism with the restriction enzyme TaqI and maps to the short arm of chromosome 9. Of the remaining two sequences, one maps to chromosome 22 and the other maps to the short arm of chromosome 6. pCN1A, which contains the 5' untranslated regions and all the coding exons of N-ras only hybridized to the chromosome 1 site. No polymorphisms have been found for pCN1 with TaqI, MspI, BclI, BglI, EcoRI, BstXI, XbaI, BamHI, BglII or HindIII.

Chromosomes, Human↗
PubMed1991

An investigation of ring and dicentric chromosomes found in three Turner's syndrome patients using DNA analysis and in situ hybridisation with X and Y chromosome specific probes.

We have studied three patients with features of Turner's syndrome, two with a 45,X/46,X,r(?) and the third with a 45,X/46,X,dic?(Y) karyotype. Because Turner's syndrome patients with a mosaic karyotype containing a Y chromosome are known to have a high risk of developing gonadal tumours, we used DNA analysis and in situ hybridisation with X and Y specific probes to identify the chromosomal origin of the rings and dicentric chromosomes in the three index patients. Both ring chromosomes were shown to be of X origin, while the dicentric was composed of Y chromosome material. We discuss the importance of using a combination of molecular and cytogenetic analyses in such cases.

Adolescent↗
PubMed1980

A reassessment of the karyotype of Papio ursinus. Homoeology between human chromosome 15 and 22 and a characteristic submetacentric baboon chromosome.

The Giemsa-banded karyotype of the chacma baboon, Papio ursinus, was shown to be identical to that of Papio hamadryas. Comparison of G-banded P. ursinus (PUR) chromosomes with those of man (HSA) showed close morphological homoeology between PUR and HSA chromosomes 5, 8, 12, 19, and X, and partial homology for seven and 22 and was the only Papio chromosome containing a nucleolar organizer region (NOR). This baboon chromosome, therefore, shows genetic homoeology with human acrocentrics for a least 18S and 28S rRNA gene loci. It is postulated that HSA 15 and 22 originated from the fission of a larger submetacentric chromosome in a lower primate.

Animals↗
PubMed1999

Chromosome Workshop: chromosomes 11, 14, and 15.

This report describes linkage data presented at the Workshop on Chromosomes 11, 14, and 15 at the Sixth World Congress of Psychiatric Genetics in Bonn, Germany, together with relevant linkage data submitted to the chair and co-chair, and it is presented in the context of the previous literature concerning these chromosomes. We have attempted to collate current linkage data to provide a guide to potentially interesting findings on chromosomes 11, 14, and 15 for the phenotypes of bipolar disorder, schizophrenia, alcoholism, autism, and spelling and reading disability. We discuss methodological limitations and provide chromosome ideograms and tables summarizing findings to date. The most promising region currently appears to be 15q13-q15 in the region of the alpha 7 nicotinic receptor for the phenotype of schizophrenia (and, perhaps, more generally for functional psychosis). Additionally, 15q11-q13 in the region of GABRB3 holds interest as a potential site of a susceptibility gene for autism. Two regions on chromosome 11, 11p15 in the region of tyrosine hydroxylase gene and 11q22-q23 in the region of DRD2, continue to retain some interest for functional psychosis.

Alcoholism↗
PubMed1992

Mechanisms of ring chromosome formation in 11 cases of human ring chromosome 21.

We studied the mechanism of ring chromosome 21 (r(21)) formation in 13 patients (11 unique r(21)s), consisting of 7 from five families with familial r(21) and 6 with de novo r(21). The copy number of chromosome 21 sequences in the rings of these patients was determined by quantitative dosage analyses for 13 loci on 21q. Nine of 11 r(21)s, including the 5 familial r(21)s, showed no evidence for duplication of 21q sequences but did show molecular evidence of partial deletion of 21q. These data were consistent with the breakage and reunion of short- and long-arm regions to form the r(21), resulting in deletion of varying amounts of 21q22.1 to 21qter. The data from one individual who had a Down syndrome phenotype were consistent with asymmetric breakage and reunion of 21q sequences from an intermediate isochromosome or Robertsonian translocation chromosome as reported by Wong et al. Another patient, who also exhibited Down syndrome, showed evidence of a third mechanism of ring formation. The likely initial event was breakage and reunion of the short and long arms, resulting in a small r(21), followed by a sister-chromatid exchange resulting in a double-sized and symmetrically dicentric r(21). The phenotype of patients correlated well with the extent of deletion or duplication of chromosome 21 sequences. These data demonstrate three mechanisms of r(21) formation and show that the phenotype of r(21) patients varies with the extent of chromosome 21 monosomy or trisomy.

Alleles↗
PubMed1977

Chromosomes of lemuriformes. II. Chromosome polymorphism in Lemur fulvus collaris (E. Geoffroy 1812).

Two previously unreported diploid numbers, 2N = 50 and 2N = 51, from five individual Lemur fulvus collaris are described. In both chromosome complements, the nombre fondamental is 64. The 2N = 50 complement is composed of 7 pairs of bi-armed chromosomes, 17 pairs of acrocentric chromosomes with small short arms, and acrocentric sex chromosomes. The 2N = 51 complement is identical with these exceptions: Only one member equivalent to bi-armed pair 6 of L.f. collaris (2N = 50) is present, and two extra acrocentrics are found in the 2N = 51 complement. G-banding analyses suggest that these chromosomes are a heteromorphic pair of the Robertsonian type. This conculsion is supported by evidence from studies of meiotic pairing relationships of the three chromosomes and the complements of hybrids resulting from interspecific matings. Comparison of the 2N = 50 and 2N = 51 complements with a published 2N = 48 complement suggests that these new karyotypes do not provide a lineal link between the 2N = 52 and 2N = 48 karyotypes (Rumpler, Y., and R. Albignac 1969 C.R. Soc. Biol., 163: 1989-1992).

Animals↗
PubMed1994

Expression of an X-linked HMG-lacZ transgene in mouse embryos: implication of chromosomal imprinting and lineage-specific X-chromosome activity.

X-chromosome activity in female mouse embryos was studied at the cellular level using an X-linked lacZ transgene which encodes beta-galactosidase (beta-Gal). Translation of maternal RNA in oocytes is seen as beta-Gal activity that persists into early cleavage-stages. Zygotic transcription of the transgene from the maternal X chromosome (Xm) is first found at about the 8-cell stage. By contrast, expression of the lacZ transgene on the paternal X chromosome (Xp) is not seen until later at the 16-32-cell stage. Preferential inactivation of Xp occurs in the mural trophectoderm, the primitive endoderm, and derivatives of the polar trophectoderm, but a small number of cells in these lineages may still retain an active paternal X chromosome. X inactivation begins at 3.5 days in the inner cell mass but contrary to previous findings the process is not completed in the embryonic ectoderm by 5.5 to 6.0 days. Regional variation in beta-Gal activity is also observed in the embryonic ectoderm during gastrulation which may be related to the specification of cell fates. Random inactivation of Xp and Xm ensues in all somatic tissues but the process is completed at different times in different tissues. The slower progression of X inactivation in tissues such as the notochord, the heart, and the embryonic gut is primarily due to the persistent maintenance of two active X chromosomes in a significant fraction of cells in these tissues. Recent findings on the methylation of endogenous X-linked genes suggest that the prolonged expression of beta-Gal might also be due to the different rate of spreading of inactivation along the X chromosome to the lacZ transgene locus in different tissues.

Animals↗
PubMed1984

Further studies on the asymmetry of chromosome 15 duplication in trisomic leukemias of heterozygous origin: preferential status of the AKR chromosome.

Four combinations of translocation heterozygotes with cytogenetically distinct chromosomes 15 were used to investigate whether the T-cell leukemia-associated preferential duplication of the AKR-derived chromosome 15 (AKR-15) is determined by factors within this chromosome, or is due to genes within the AKR genotype, but outside chromosome 15. Two of the four combinations were also used to determine whether the AKR-15 duplication preference could be cancelled by MCF-viremia in permissive F1 hybrids. Chemically and virally induced 15-trisomic leukemias showed the same AKR-15 duplication preference, which was due to some autonomous property of AKR-15 itself. It was maintained in (C57BL 6;15 X C57BL) F1 leukemias, where 6;15 is the only AKR-derived chromosome propagated on the C57BL/background. In the (C57BL 6;15 X AKR) F1 hybrid cross where both chromosomes 15 are of AKR origin, duplication occurred at random. To approach the second question, MCF viremia was induced by neonatal virus inoculation into permissive (AKR 6;15 X B6Fv-In) F1 hosts. The preferential duplication status of the AKR-derived 6;15 remained unchanged.

Animals↗
PubMed1992

A DNA library from an individual Beta patellaris chromosome conferring nematode resistance obtained by microdissection of meiotic metaphase chromosomes.

We have used a standard protocol established for human chromosomes to create a chromosome-specific plasmid library from a Beta patellaris chromosome conferring nematode resistance. A monosomic addition line was chosen carrying 18 sugar-beet (Beta vulgaris L.) and one wild-beet (B. patellaris) chromosome. The wild-beet chromosome can readily be identified as a univalent during metaphase I of meiosis. Highly synchronized meiotic material was used to excise the univalents from four pollen mother cells. The chromatin was lysed in a 1 nl collection drop, the DNA purified and restricted with Rsa I, ligated into a vector containing universal sequencing primers, and amplified by the polymerase chain reaction. The amplified DNA was inserted into a standard plasmid vector and cloned. Approximately 23,000 recombinant plasmids were obtained of which 15,800 could be utilized. Their insert sizes ranged from 80 to 700 bp with an average of 130 bp. 61 clones were tested in more detail by genomic Southern hybridization with sugar-beet and wild-beet DNA. Of these 32 plasmids (52%) contained single-copy inserts, 11 (18%) were specific for wild-beet DNA indicating that the DNA cloned originates in the univalent chromosome. The application of this technique for establishing high-density RFLP maps for discrete regions of plant genomes is discussed.

Animals↗