[Plicated tongue and chromosome abnormalities in families with Down's syndrome].
Explore the source record for details and available documents.
SEARCH · Search PubMed
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.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
It was previously shown that more than half of the human oocytes obtained from IVF patients of advanced reproductive age are aneuploid, due to meiosis I and meiosis II errors. The present paper further confirms that 61.8% of the oocytes tested by fluorescent probes specific for chromosomes 13, 16, 18, 21 and 22 are abnormal, representing predominantly chromatid errors, which are the major source of aneuploidy in the resulting embryos. Almost half of the oocytes with meiosis I errors (49.3%) are prone to sequential meiosis II errors, which may lead to aneuploidy rescue in 30.8% of the cases. Half of the detected aneuploidies (49.8%) are of complex nature with involvement of two or more chromosomes, or the same chromosome in both meiotic divisions. The aneuploidy rates for individual chromosomes are different, with a higher prevalence of chromosome 21 and 22 errors. The origin of aneuploidy for the individual chromosomes is also not random, with chromosome 16 and 22 errors originating more frequently in meiosis II, and chromosome 18, 13 and 21 errors in meiosis I. There is an age dependence not only for the overall frequency of aneuploidies, but also for each chromosome error, aneuploidies originating from meiosis I, meiosis II, and both meiosis I and meiosis II errors, as well as for different types of aneuploidies. The data further suggest the practical relevance of oocyte aneuploidy testing for detection and avoidance from transfer of the embryos deriving from aneuploid oocytes, which should contribute significantly to the pregnancy outcomes of IVF patients of advanced reproduction age.
Bloom syndrome is an autosomal recessive genetic disease. Cells from patients with this disease are characterized by high levels of chromosome aberrations and sister chromatid exchanges. We show here that the frequency of these chromosomal changes is markedly reduced when the cells are grown in the presence of certain protease inhibitors. In relation to other published data, our results suggest that the primary defect of Bloom syndrome cells may be related to the production of abnormally large amounts of agents, presumably active oxygen species, which are capable of acting like tumor promoters.
The case of a 25-year-old man with the characteristic features of malignant histiocytosis (proliferation of abnormal histiocytic cells with erythrophagocytosis, hepatosplenomegaly, increased serum acid phosphatase, hypercalcemia, and bone pain) is reported. Chromosome studies revealed a near tetraploid karyotype with a pair of marker chromosomes. A few hours after initiation of chemotherapy with cyclophosphamide, Adriamycin (doxorubicin), vincristine, and prednisolone (CHOP regimen), the patient developed an acute ascending paralysis. Cerebrospinal fluid (CSF) findings were consistent with a diagnosis of Guillain-Barré Syndrome. On the next day, disseminated intravascular coagulation (DIC) with severe hyperfibrinolysis occurred. After intensive chemotherapy, complete remission could be achieved.
A female infant presented at seven weeks of age with failure to thrive, progressively severe pancytopenia, hypogammaglobulinemia and, mucosal ulceration. Bone marrow morphology showed severed megaloblastic changes in the myeloid series with a shift to the left and an increased number of blasts with abnormal morphology. Erythroid precursors and megakaryocytes were markedly decreased. Cytogenetic studies showed marked aneuploidy and increased chromosomal breakage. Treatment with high doses of vitamin B12 resulted in a dramatic clinical response with hematological values becoming normal. The patient's serum showed absence of transcobalamin II, and very little TC I and TC III binding. The patient's parents had only half the lower limits of normal transcobalamin II. QUSO G-32 was used for separation of transcobalamins, and the results were confirmed by Sephacryl S-300. This case illustrates the usefulness of QUSO in the rapid diagnosis of transcobalamin II deficiency.
A 1-year-old boy was referred to us because of abnormal external genitalia; that is, his penis was kinked toward the perineal region. We diagnosed hypospadias. Chromosomal examination was performed on a sample of peripheral blood, the karyotype was 46,X+mar. Detailed karyotypic analysis revealed that the short arm of the marker chromosome originated on the ninth chromosome, but we could not determine whether the long arm was part of the Y chromosome, even with the use of quinacrine mustard. The sex-determining region of the Y was detected using the polymerase chain reaction method, which suggested that the long arm of the marker chromosome was delivered from the short arm of the Y chromosome.
Karyotypic analysis of a gastric stromal tumor with the histologic and immunohistochemical features of a malignant, uncommitted lesion revealed clonal monosomies of chromosomes 14 and 22. Such changes, together with loss of chromosomes 15 and 18, as well as structural rearrangements involved chromosome 1, have been previously reported in gastrointestinal stromal tumors with smooth muscle differentiation. We suggest that monosomies of chromosomes 14 and 22 are early events in the malignant transformation of the mesenchymal cell-originating gastrointestinal stromal tumors.
Four balanced chromosomal translocation, deletion of chromosome 15, and a break in chromosome 11 were detected in 100 G-banded metaphases of cultured lymphocytes of a patient with Werner's syndrome. We observed aneuploidy that included both trisomies and monosomies for various chromosomes. Halogenated analogs of thymidine in low doses increased significantly the incidence of chromosome aberrations accompanied by fragments. 5-Iododeoxyuridine induced lesions in centromeric regions of B-group chromosomes in 44.4% of all the cases of breaks. A hypothesis is proposed about the existence of a special mechanism for genetic control in changes in the cell nucleus and mitotic chromosome transformation. This mechanism can be manifested after the application of halogenated analogs of thymidine. The mutation involved in Werner's syndrome is presumably related to this mode of genetic control.
We have identified an identical reciprocal translocation between the long arms of chromosomes 3 and 21 with breakpoints at bands 3q26 and 21q22, [t(3;21)(q26;q22)], in the malignant cells from five adult patients with therapy-related myelodysplastic syndrome (t-MDS) or acute myeloid leukemia (t-AML). Primary diagnoses were Hodgkin's disease in two patients and ovarian carcinoma, breast cancer, and polycythemia vera in one patient each. Patients had been treated with chemotherapy including an alkylating agent for their primary disease 1 to 18 years before the development of t-MDS or t-AML. We have not observed the t(3;21) in over 1,500 patients with a myelodysplastic syndrome or acute myeloid leukemia arising de novo or in over 1,000 patients with lymphoid malignancies. We have previously reported that the t(3;21) occurs in Philadelphia chromosome-positive chronic myelogenous leukemia (CML). Thus, the t(3;21) appears to be limited to t-MDS/t-AML and CML, both of which represent malignant disorders of an early hematopoietic precursor cell. These results provide a new focus for the study of therapy-related leukemia at the molecular level.
Two quite distinct neoplasia-associated karyotypic patterns are emerging. One is characterized by simple and disease-specific abnormalities, and the other is characterized by multiple and nonspecific aberrations. The former pattern is typical of most leukemias and lymphomas and of some mesenchymal tumors, but it is rare in epithelial neoplasms. The latter pattern is found in most epithelial tumor types, in several mesenchymal neoplasms, but in only a few hematologic malignancies. Primary chromosome aberrations, which are believed to be essential in establishing the neoplasm, and secondary changes, which are considered to be important in tumor progression, may be distinguished in the tumors characterized by simple and disease-specific abnormalities. Here, we propose that these aberrations are genetically and hence, most likely, functionally distinct. Primary abnormalities lead to specific gene rearrangements, whereas secondary chromosomal changes result in large-scale genomic imbalances. According to this hypothesis, there are no unbalanced primary aberrations, only secondary imbalances masquerading as primary. This proposition has a number of conceptual ramifications. First, the genetic mechanisms underlying tumor initiation and progression would seem to be totally different. Second, the elucidation of the molecular consequences of the secondary aberrations will be an arduous task, even if one were to adhere to the view that cytogenetically identified genomic imbalances may be reduced to simple gains or losses of single oncogenes or tumor suppressor genes. Third, the cytogenetic diagnosis of neoplasms will have to take into account that an unbalanced "primary" abnormality is secondary to a submicroscopic, truly primary change of major diagnostic and prognostic importance.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Spectral karyotyping (SKY) is a novel technique based on the simultaneous hybridization of 24 fluorescently labeled chromosome painting probes. It provides a valuable addition to the investigation of many tumors that can be difficult to define by conventional banding techniques. One such tumor is neuroblastoma, which is often characterized by poor chromosome morphology and complex karyotypes. Ten primary neuroblastoma tumor samples initially analyzed by G-banding were analyzed by SKY. In 8/10 tumors, we were able to obtain additional cytogenetic information. This included the identification of complex rearrangements and material of previously unknown origin. Structurally rearranged chromosomes can be identified even in highly condensed metaphase chromosomes. Following the SKY results, the G-banding findings were reevaluated, and the combination of the two techniques resulted in a more accurate karyotype. This combination allows identification not only of material gained and lost, but also of breakpoints and chromosomal associations. The use of SKY is therefore a powerful tool in the genetic characterization of neuroblastoma and can contribute to a better understanding of the molecular events associated with this tumor.
A cytogenetic study on 25 breast fibroadenomas from 17 women is reported. Seven tumors in five patients showed clonal structural chromosome changes. In three patients the breaks involved chromosome 12, occurring in two tumors in band 12p12 and in band 12q15 in all three tumors of one patient. The finding of an identical aberration, t(11;12)(q21;q15), in three adenomas from the same patient strongly suggests a clonal origin of multiple fibroadenomas of the breast.
Explore the source record for details and available documents.
Fluorescence in situ hybridization (FISH) with single-color chromosome-specific probes was used to study the rates of disomy for chromosome 1, 16, X, and Y in sperm of fertile and infertile subjects. Diploidy rates were studied using a two-color cocktail of probes for chromosomes 17 and 18 in the same sperm samples. Two-color methodology was not available at the outset of the study. A total of 450,580 spermatozoa were studied from 21 subjects (9 fertile, 12 infertile). Significant differences were observed in the disomy rates between chromosomes with the highest frequency observed for chromosome 16 (0.17%) and the lowest for the Y chromosome (0.10%). No differences were observed between fertile and infertile subjects for either diploidy or disomy. Total disomy rates for chromosomes 1, 16, X and Y ranged from 0.34% to 0.84% among infertile subjects, and 0.32% to 0.61% among fertile subjects. Our data suggest that generalized aneuploidy in sperm is not a major contributor to unexplained infertility.
Refine your search to explore more results.