Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “CHROMOSOMES”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,531 records · Page 85Linked to original sources
PubMed2003

Small supernumerary marker chromosome derived from proximal p-arm of chromosome 2: identification by fluorescent in situ hybridization.

Conventional cytogenetics detected an interstitial deletion of proximal region of p-arm of chromosome 2 in a 6-month-old boy with a phenotype slightly resembling Down's syndrome. The deletion was inherited from the father, whose karyotype revealed a small ring-shaped marker chromosome, in addition to interstitial deletion. Fluorescence in situ hybridization identified the marker, which consisted of the proximal region of the p-arm of chromosome 2, including a part of its centromere. This case shows that molecular cytogenetic analysis can reveal the mechanism of the formation of the marker chromosome.

Chromosome Aberrations↗
PubMed1992

Analysis of chromosome 21 yeast artificial chromosome (YAC) clones.

Chromosome 21 contains genes relevant to several important diseases. Yeast artificial chromosome (YAC) clones, because they span > 100 kbp, will provide attractive material for initiating searches for such genes. Twenty-two YAC clones, each of which maps to a region of potential relevance either to aspects of the Down syndrome phenotype or to one of the other chromosome 21-associated genetic diseases, have been analyzed in detail. Clones total approximately 6,000 kb and derive from all parts of the long arm. Rare restriction-site maps have been constructed for each clone and have been used to determine regional variations in clonability, methylation frequency, CpG island density, and CpG island frequency versus gene density. This information will be useful for the isolation and mapping of new genes to chromosome 21 and for walking in YAC libraries.

Chromosome Mapping↗
PubMed2003

Fine mapping of chromosome 3 in uveal melanoma: identification of a minimal region of deletion on chromosomal arm 3p25.1-p25.2.

To identify minimal common areas of allelic loss on chromosome 3, we have mapped both arms of the chromosome in 21 uveal melanomas that did not show monosomy 3 in our previous allelotype study. DNA was isolated from microdissected paraffin sections and amplified by PCR. In an initial screening, 14 microsatellite markers on chromosomal arm 3p and 13 on chromosomal arm 3q were used. Loss of heterozygosity for at least one marker was found in 9 of 21 tumors (43%) on 3p and 8 of 21 tumors (38%) on 3q. The initial analysis defined two common regions of allelic loss on 3p, a 7.3-Mb region between markers D3S1263 and D3S3510 spanning 3p25.3-24.3 and a larger region between markers D3S1578 and D3S1284. The two common regions of allelic loss were further mapped with an additional 14 microsatellite markers. A 1.4-Mb minimal region of allelic loss was identified between microsatellite markers D3S3610 and D3S1554 on 3p25.1-3p25.2. A total of 10 tumors had allelic loss in this region; 2 of these tumors had corresponding putative homozygous deletions. These homozygous deletions may further narrow the region of interest to 0.1 Mb. This 1.4-Mb minimum region of deletion includes several genes that might be involved in the carcinogenesis of uveal melanoma as well as other important tumor types.

Chromosome Deletion↗
PubMedDate not supplied

[A case of deletion of the short arm of the chromosome 21 (21p-) (christchurch chromosome) discovered prenatally:clinical and cytogenetic data].

Results of cytogenetic research of placental villi and amniotic fluid cells culture of the 22-weeks-old fetus with multiple congenital malformations (MCM) are presented. The absence of the short arm in one of the homologue of the chromosome 21 was revealed. Cytogenetic analysis of the fetus father's blood lymphocytes determined the similar chromosome. Further research of the father's karyotype made by FISH-method using specific DNA samples had discovered the absence of subtelomeric parts in the short arm of the chromosome 21 that might be considered as a deletion. It was suggested that the effect of position and interaction of genes could play a key role in appearing of MCM in the fetus in the case when the 21p-chromosome was transferred to it from the healthy parents.

Abnormalities, Multiple↗
PubMed2006

[Genetic analysis of translocation of chromosome t(4;9) in a child with rare chromosome abnormality].

A 10-month-old boy suspected of genetic abnormality was admitted for fever and coughing. Routine G-banding chromosome analysis of the peripheral blood lymphocytes and hereditary pattern analysis on the basis of the karyotypes and disease history revealed that the karyotype of the boy's mother was 46, XX,t(4;9)(q31;p24), and that of the boy was XY,der(9)t(4;9)(q31;p24)mat. The mother was identified as a carrier of balanced translocation of the chromosome who gave the abnormal chromosome 9 to her son, and she had only a chance of 1:18 to have a normal offspring. This case reiterates the importance of antemarital examination and prenatal diagnosis for preventing chromosomal diseases.

Abnormalities, Multiple↗
PubMed1990

Detection of numerical chromosomal abnormalities in neoplastic hematopoietic cells by in situ hybridization with a chromosome-specific probe.

The feasibility of using molecular hybridization techniques for the detection of malignant clones that contain numerical chromosomal abnormalities was tested in clinical specimens from patients who had hematologic malignancies. A biotinylated DNA probe specific for chromosome 9 was used for in situ hybridization to interphase and terminally differentiated cells, and fluoresceinated avidin or avidin followed by biotinylated alkaline phosphatase was used for probe detection. In a blinded analysis of ten clinical samples from patients with hematologic malignancies and cytogenetically documented monosomy 9 or trisomy 9, the abnormality was identified correctly in each of five cases of monosomy 9 and five cases of trisomy 9. In two cases of trisomy 9, the detection of this numerical chromosomal abnormality in nuclei of segmented neutrophils permitted the deduction that some granulocytic cells were derived from the abnormal clone, but were still capable of terminal differentiation. Analysis of the position of the probe signal in such nuclei did not disclose any ordered localization of the chromosome 9 homologues with respect to segmentation. These results demonstrate that interphase cytogenetic analysis is feasible in peripheral blood and bone marrow specimens, and that this technique may be a useful adjunct to conventional cytogenetic analysis for the clinical management of patients with hematopoietic malignancies.

Bone Marrow↗
PubMed1990

Chromosome assignment by polymerase chain reaction techniques: assignment of the oncogene FGF-5 to human chromosome 4.

We describe a new chromosomal assignment method based on the polymerase chain reaction mediated amplification of target sequences in DNAs from somatic cell hybrids. The new method is faster, much more sensitive and less labor intensive than the standard method of chromosome assignment by Southern hybridization analysis of somatic cell hybrid DNAs. The feasibility of the new approach was demonstrated by verifying the assignment of the previously mapped acidic fibroblast growth factor gene to human chromosome 5. The method was employed to assign the related oncogene, FGF-5, to human chromosome 4.

Animals↗
PubMed1990

[Chromosomes and chromosome disorders].

The risk of bearing a child with chromosomal defects increases once the mother reaches the age of 35; the principal indication for chromosomal examination of the fetus is that the pregnant woman is "older". Chromosomal examination of new-born babies is indicated if it is suspected that dysmorphic features may depend on cytogenetic deviation. Other indications include suspicion of so-called fragile X syndrome or rare congenital disorders such as Fanconi's anemia, Xeroderma pigmentosum etc. Chromosomal examination is routine today in investigation of suspected or verified hematological diseases. Nevertheless the possibilities of cytogenetic techniques have not yet been used to the full in diagnostics, assessment of prognoses, choice of therapy and follow-up of disease.

Chromosome Aberrations↗
PubMed1988

Assignment of the functional gene for human adrenodoxin to chromosome 11q13----qter and of adrenodoxin pseudogenes to chromosome 20cen----q13.1.

Adrenodoxin is a small iron/sulfur protein serving as an electron-transport intermediate for all mitochondrial forms of cytochrome P450. Southern blots of normal genomic DNA cleaved with six restriction endonucleases probed with full-length human adrenodoxin cDNA revealed complex patterns indicating the presence of multiple adrenodoxin genes. Southern blots of DNA from a panel of mouse/human somatic cell hybrids identified cross-hybridizing adrenodoxin DNA in two loci, chromosome 11q13----qter and chromosome 20cen----q13.1. Examination of adrenodoxin clones from a genomic DNA library in phage lambda revealed some clones bearing gene fragments interrupted by introns and other clones bearing processed pseudogenes. By probing the mouse/human hybrids with unique intronic DNA and by correlating restriction maps of the phage clones with that of uncloned genomic DNA, we show that the authentic transcribed adrenodoxin gene lies on chromosome 11, while pseudogenes lie on chromosome 20.

Adrenodoxin↗
PubMed1988

The gene for cystathionine beta-synthase (CBS) maps to the subtelomeric region on human chromosome 21q and to proximal mouse chromosome 17.

The human gene for cystathionine beta-synthase (CBS), the enzyme deficient in classical homocystinuria, has been assigned to the subtelomeric region of band 21q22.3 by in situ hybridization of a rat cDNA probe to structurally rearranged chromosomes 21. The homologous locus in the mouse (Cbs) was mapped to the proximal half of mouse chromosome 17 by Southern analysis of Chinese hamster X mouse somatic cell hybrid DNA. Thus, CBS/Cbs and the gene for alpha A-crystalline (CRYA1/Crya-1 or Acry-1) form a conserved linkage group on human (HSA) chromosome region 21q22.3 and mouse (MMU) chromosome 17 region A-C. Features of Down syndrome (DS) caused by three copies of these genes should not be present in mice trisomic for MMU 16 that have been proposed as animal models for DS. Mice partially trisomic for MMU 16 or MMU 17 should allow gene-specific dissection of the trisomy 21 phenotype.

Animals↗
PubMed1986

[Fragile sites on human chromosomes and cancer-specific chromosomal rearrangements].

Heritable fragile sites are specific points on human chromosomes which appear as nonstaining gaps or breaks under certain physiological conditions and are inherited in a Mendelian codominant fashion. Recent findings of a correlation between fragile sites and breakpoints involved in specific chromosomal rearrangements seen in some neoplasias suggest that fragile sites may be unique sites particularly susceptible to chromosome breakage and rearrangement under in vivo physiological conditions. The majority of known fragile sites, including fragile X, are classified in the folate-sensitive group and are expressed under conditions of thymidylate stress. In thymidine-auxotrophic somatic cell hybrids constructed by cell fusion between fragile X cells and thymidylate synthase-negative mouse mutant cells, we have shown that thymidine deprivation alone can induce the expression of fragile X, suggesting that the primary DNA structure itself is responsible for its expression. Elucidation of the DNA structure of fragile sites may provide a clue to the understanding of genetic instability in the human genome and its possible involvement in cancer-specific chromosomal rearrangements.

Animals↗
PubMed1993

The retinoblastoma-related gene, RB2, maps to human chromosome 16q12 and rat chromosome 19.

A retinoblastoma-related human gene, referred to as RB2, has been cloned based on sequence homology of the E1A-binding domain of the retinoblastoma gene. Structural homology with the retinoblastoma gene suggests a possible function of RB2 as a tumor suppressor gene. In this study, we have mapped this gene to human chromosome 16q12.2 and rat chromosome 19, using fluorescence in situ hybridization and somatic hybrid cell analysis, respectively. Based on known syntenic relationships among human, rat and mouse, the data suggest that the mouse homolog resides on chromosome 8. Deletions of chromosome 16q have been found in several human neoplasias (including breast, ovarian, hepatic, and prostatic cancers) which is in support of an involvement of RB2 in human cancer as a tumor suppressor gene.

Animals↗
PubMed1994

Concordance between parental origin of chromosome 13q loss and chromosome 6p duplication in sporadic retinoblastoma.

Two hypotheses are capable of explaining nonrandom loss of one parent's alleles at tumor suppressor loci in sporadic cases of several pediatric cancers, including retinoblastoma--namely, preferential germ-line mutation or chromosome imprinting. We have examined 74 cases of sporadic retinoblastoma for tumors in which at least two genetic events--loss of heterozygosity for chromosome 13q markers and formation of an isochromosome 6p--have occurred. Sixteen cases were found to contain both events. In 13 of 16 such tumors, the chromosomes 13q that were lost and chromosomes 6p that were duplicated are derived from the same parent. These data may be explained within the framework of the genome imprinting model but are not predicted by preferential germ-line mutation.

Chromosome Deletion↗
PubMedDate not supplied

[An analysis of the asynchronous condensation of homologous chromosomes in patients with chromosomal anomalies and their parents].

The aim of investigation was to study asynchronous condensation of differentially segmented homologous chromosomes in lymphocytes of peripheral blood, as a variant of karyotype instability in families which has a children with multiple malformations and cytogenetic defects. Automatically calculated the correlation between every pair of homologous chromosomes. After that we made the correlation diagrams for all patients. Our study showed that children with multiple malformations and cytogenetic defects and their parents has low correlation of banding structure between homologs. The length and segmentation one of homologs in every pair is conform to more early condensation stage. We made a conclusion about presence of asynchronous condensation homologous chromosome. As a control we perform the same investigation of 6 families with healthy children. We found high correlation between homologous chromosomes, namely synchronous condensation homologous pairs in all patients of this group. Asynchronous condensation was found only in all members of families which has a child with cytogenetic defect.

Abnormalities, Multiple↗
PubMed1995

The IL-9 receptor gene (IL9R): genomic structure, chromosomal localization in the pseudoautosomal region of the long arm of the sex chromosomes, and identification of IL9R pseudogenes at 9qter, 10pter, 16pter, and 18pter.

Cosmids containing the human IL-9 receptor (R) gene (IL9R) have been isolated from a genomic library using the IL9R cDNA as a probe. We have shown that the human IL9R cDNA as a probe. We have shown that hte human IL9R gene is composed of 11 exons and 10 introns, stretching over approximately 17 kb, and is located within the pseudoautosomal region of the Xq and Yq chromosome, in the vicinity of the telomere. Analysis f the 5' flanking region revealed multiple transcription initiation sites as well as potential binding motifs for AP1, AP2, AP3, Sp1, and NF-kB, although this region lacks a TATA box. Using the human IL9R cosmid as a probe to perform fluorescence in situ hybridization, additional signals were identified in the subtelomeric regions of chromosomes 9q, 10p, 16p, and 18p. IL9R homologs located on chromosomes 16 and 10 were completely sequenced. Although they are similar to the IL9R gene (approximately 90% identity), none of these copies encodes a functional receptor: none of them contains sequences homologous to the 5' flanking region or exon 1 of the IL9R gene, and the remaining ORFs have been inactivated by various point mutations and deletions. Taken together, our results indicate that the IL9R gene is located at Xq28 and Yq12, in the long arm pseudoautosomal region, and that four IL9R pseudogenes are located on 9q34, 10p15, 16p13.3, and 18p11.3, probably dispersed as the result of translocations during evolution.

Alternative Splicing↗
PubMed1979

[Human chromosome polymorphism and disordered reproductive function. II. C-variant chromosomes].

C-stained polymorphic variants of chromosomes 1, 9, 13--16, 21, 22 and Y were studied in married couples with reproductive failure (200 individuals) and in control couples having normal children and no spontaneous abortions and stillbirths. Location of heterochromatic segments, their size and heteromorphism of homologues were estimated. The individuals with reproductive failure were carriers of variants of chromosomes 9 and acrocentrics with higher content of heterochromatic material as well as with heterochromatic chromosome 9 significantly more frequently as compared with control individuals.

Abortion, Habitual↗
PubMed2004

Preimplantation diagnosis of repeated miscarriage due to chromosomal translocations using metaphase chromosomes of a blastomere biopsied from 4- to 6-cell-stage embryos.

OBJECTIVE: To evaluate the safety and accuracy of karyotyping the blastomere chromosomes at metaphase in the natural cell cycle for preimplantation diagnosis. DESIGN: A pilot study. SETTING: A private infertility clinic and a university laboratory. PATIENT(S): Eleven patients undergoing IVF and preimplantation diagnosis. INTERVENTION(S): Intact human embryos at the 4- to 6-cell stage and human-mouse heterokaryons were cultured and checked hourly for disappearance of the nuclear envelope. After it disappeared, the metaphase chromosomes were analyzed by fluorescence in situ hybridization. MAIN OUTCOME MEASURE(S): Percentage of analyzable metaphase plates and safety and accuracy of the method. RESULT(S): The success rate of electrofusion to form human-mouse heterokaryons was 87.1% (27/31), and analyzable chromosomes were obtained from 77.4% (24/31) of the heterokaryons. On the other hand, disappearance of the nuclear envelope occurred in 89.5% (17/19) of the human embryos and it began earlier than that in the heterokaryons. Analyzable chromosomes were obtained and their translocation sites were identified in all blastomeres biopsied from the 17 embryos. After the biopsy, 67.0% of the embryos could develop to the blastocyst stage. CONCLUSION(S): The natural cell cycle method reported herein requires frequent observation, but it is safe, with no artificial effects on the chromosomes and without loss of or damage to blastomeres, which occurred with the electrofusion method. Using the natural cell cycle method, we could perform preimplantation diagnosis with nearly 100% accuracy.

Abortion, Habitual↗
PubMed2001

DNA amplification and chromosomal translocations are accompanied by chromosomal instability: analysis of seven human colon cancer cell lines by comparative genomic hybridization and spectral karyotyping.

Genetic instability in human cancers is classified as chromosomal instability (CIN) or microsatellite instability (MIN). DNA amplification and translocations are observed frequently in various cancers. We used comparative genomic hybridization (CGH) and spectral karyotyping (SKY) to study seven human colon cancer cell lines and investigate the relations among genetic instability, DNA amplification, and chromosomal translocations. DNA amplification was found in five cell lines (COLO320DM, COLO201, WiDr, CoCM-1, and CACO-2), and all were aneuploid. In these five cell lines, segments of chromosomes were translocated to other chromosomes. In contrast, cell lines with MIN, DLD-1, and LoVo did not show DNA amplification. The LoVo cells with MIN were considered near diploid and contained translocations. These findings suggest that DNA amplification and chromosomal translocations are accompanied by CIN.

Colonic Neoplasms↗