Active clinical trials for "Chromosome Aberrations"

Granulocyte Colony Stimulating Factor (GCSF) is used extensively as a means of mobilising donor peripheral blood stem cells as an alternative to bone marrow harvesting for the purpose of recipient stem cell transplantation. The principal objective of the research is to study any longterm genetic effects of GCSF in the peripheral blood white cells of unrelated blood stem cell donors. The study subjects will be Retrospective and Prospective voluntary unrelated donors on the Anthony Nolan Bone Marrow Registry being harvested at the Royal Free Hospital and University College Hospital, London and British Bone Marrow Registry donors harvested at the Royal Free Hospital and BUPA Glen Vale in Bristol. All participants in the Prospective Arm will be asked to donate one 5-10ml sample of blood at study entry prior to stem cell donation and further samples at 120 and 360 days post donation. Those found to carry aneuploid cell clones at these time points will be asked for a further 5-10ml blood sample at least twice - at the end of 24 months and 36 months respectively. The Retrospective and Positive Control group will be asked to supply one 5-10ml sample of blood.

Premature ovarian failure (POF) is known to be associated with an increased risk of ocular surface disease (dry eye), likely due to the reduction of both estrogens and androgens seen in this condition. From preliminary data, we suspect that women with Turners syndrome (45, XO), a genetic abnormality that affects sex hormone levels, are also at increased risk of ocular surface disease. Comparing POF and TS women may allow us to distinguish different mechanisms for ocular surface disease, due to the different etiologies of hormonal (estrogen and androgen) alterations posed by POF and TS.

Ionizing radiation efficiently induces chromosomal aberrations (CA) and several studies of CA have now been conducted among small groups of flight crews. However, most of the studies only evaluated the unstable aberrations that reflect recent exposures, but not long-term cumulative cosmic radiation exposure. Chromosome painting by fluorescence in situ hybridization (FISH) is a widely used and established cytogenetic method for detecting stable aberrations such as translocations. Thus, FISH can be used for estimating chromosomal damage from cumulative radiation exposure. No large studies of flight crews utilizing FISH have been conducted to date. We propose a study to measure CA using FISH in a group of pilots estimated to have high comic radiation exposure based on flight histories, i.e., those with long duration flying international routes, and a comparison group of university faculty with minimal flying history. These measurements will be used to determine if pilots have elevated frequencies of CA (specifically stable translocations) as compared with the university faculty. In addition, the frequencies of CA will be examined in relation to the cumulative cosmic radiation dose to determine if there is a dose-response relationship. Individual cumulative doses will be calculated from pilot flight histories using a computer program developed by the FAA which estimates cosmic radiation does by accounting for changes in altitude and latitude, and the 11-year solar cycle at the time of the flight. We will collect information on age, lifestyle factors, diet, health history, family cancer history, and medical radiation exposures from personal interview and self-administered dietary questionaire. These factors may affect the CA frequency and so we plan to adjust for them in the statistical analyses. Pilots will be identified based on the Allied Pilots Association roster and faculty from a commercial company that maintains a database of university faculty, including those in the Chicago area. Potential participants will be notified of the study by mail and recruited/screened for eligibility over the telephone. We will compensate participants $100 for their time. A field station will be set up at a medical or health clinic convenient to the participants, where interviews Will be conducted and a peripheral blood sample collected. Participants will be notified of the overall study results and may request their personal CA results at the end of the study. Participants may also choose to have additional blood drawn, however this blood sample will be anonymized so that it cannot be linked back to the participant. Genotypic variants in DNA repair (and possibly other) genes will be evaluated for an effect on CA frequency.

An increased incidence of aneuploid pregnancies has been reported in women of advanced maternal age, with higher miscarriage rates. Cytogenetic studies in preimplantation embryos have shown elevated aneuploidy rate, particularly in women over 38 years. For these reasons, PGS has been applied to these patients to improve ongoing implantation rates, and most importantly, to decrease the risk of further miscarriages and affected offspring. In the past two years, several RCT have raised the question whether PGS is benefitial or not in AMA patients. In our experience, PGS outcome in these patients offers higher ongoing implantation rates than the previously published in RCT studies, where no benefits for PGS were found. In these papers, poor technical skills, as well as unclear patients selection could explain the reported lack of PGS benefits. Therefore, the objective of the present RCT is to analyze the outcome of IVF cycles with and without PGS in two age groups: Patients 38-39 years of age: 200 cyles per arm reaching embryo transfer should be performed Patients 40-44 years of age: 120 cycles per arm reaching embryo transfer Sample size has been calculated according to our retrospective experience with higher differences in ongoing implantation rates between cycles with and without PGS in patients of 40-44 years of age. In all patients embryo transfer will be performed on day 5. In the PGS group one cell will be biopsy in embryos with ≥5 cells on day-3 and chromosomes 13, 15, 17, 18, 21, 22, X and Y will be analyzed in two rounds. In the third round, nuclei with undoubtful or non-conclusive results will be analyzed using subtelomeric probes.

The past two decades have witnessed the development and growth of the endovascular techniques, however, this new technology is not exempt from risks, since its use requires an ionizing radiation exposure to both patients and surgeons. In this context, the long-term repercussion of this type of chronic exposure to low dose ionizing radiation of the vascular surgeons is still unknown. Although conventional dosimetry is used to monitoring the occupational radiation exposure, it doesn't take into consideration a number of individual variables such as: age, sex, exposure to other carcinogen substances or previous medical history; that may affect the radio-sensibility of each individual. Some studies suggest the use of routine cytogenetic analysis to complement the conventional dosimetry, yet the real genomic effects of chronic low dose ionizing radiation exposure is still unclear and an ideal biodosimetry marker hasn't been described. In this setting, the main objective of the present study was to determine the genomic instability associated to the chronic low dose exposure to ionizing radiation of vascular surgeons versus healthy control patients with no history of radiation exposure. The secondary endpoints were to determine the impact of demographic and clinical practice activities associated to genomic instability among both groups of patients. National, observational and transversal case control study of genomic instability among vascular surgeons chronically exposed to low dose ionizing radiation compared to healthy control patients with no previous history of radiation exposure. The peripheral blood samples of the case group were collected from vascular surgeons during the VI International Symposium of Endovascular Surgery. The blood samples were followed by a demographic and endovascular practice questionnaire. On the other hand, the samples for the control group were collected from healthy patients undergoing saphenectomy and/or phlebectomy in our department at Hospital Clínico Universitario de Valladolid. All blood samples were send to the Cancer Investigation Center at Salamanca University where three types of genomic analysis were performed: (1) fluorescence in situ hybridization (FISH) study in interphase for the chromosomes 3, 7 and 17 and locus 9p21; (2) metaphase study with G banding technique; and (3) sister chromatid exchange (SCE) metaphase study.

OBJECTIVES: I. Investigate phenotype and genotype correlations in patients with Smith-Magenis syndrome (SMS) associated with del(17p11.2). II. Clinically evaluate SMS patients with unusual deletions or duplication of proximal 17p. III. Clinically evaluate patients with Williams syndrome with molecular characterization of 7q11.23. IV. Perform clinical studies of Prader-Willi, Angelman, DiGeorge, and Shprintzen syndrome patients with unique molecular findings in 15q11q13 or 22q11.2. V. Perform genotype and phenotype correlations in Prader-Willi patients, particularly those with loss of expression of only some of the imprinted transcripts in 15q11-q13. VI. Evaluate putative Angelman syndrome patients who do not have classic large deletion, uniparental disomy, or imprinting mutations, and perform molecular studies of the Angelman gene, UBE3A, and identify mutations of this gene. VII. Investigate phenotype and genotype correlations in patients with terminal deletions of chromosome 1p.

Too much or too little genetic information (chromosome material) can cause abnormal development of the fetus or death. Each year approximately 2.5 million pregnant women are screened for Down Syndrome using invasive screening methods (amniocentesis or chorionic villus sampling). This 11 center study of 38,000 women will compare the accuracy of the several non-invasive tests in the first and second trimesters of pregnancy versus amniocentesis or diagnosis at birth to diagnose aneuploidy or Down Syndrome.

The study assesses the accuracy of cell-free DNA (cfDNA) analysis in detecting whole chromosomal aneuploidies from maternal plasma of patients with early, missed miscarriage.

This clinical study will demonstrate the accuracy of the chromosomal aberration and gene mutation markers of the AMLProfiler molecular diagnostic assay and generate clinical performance data to support a Pre-Market Approval (PMA) submission to the Food and Drug Administration for in vitro diagnostic use within the United States of America. The objective is to demonstrate the positive and negative percent agreement of each marker by comparing AMLProfiler results from multiple clinical participating sites with data generated using a laboratory developed bi-directional sequencing method generated at the molecular diagnostic reference lab. The AMLProfiler assay is a qualitative in vitro diagnostic test for the detection of AML or APL specific chromosomal aberrations (specific recurrent translocations and inversions), as well as expression of specific genetic markers in RNA extracted from bone marrow aspirates of patients with Acute Myeloid Leukemia.

The objectives of the clinical study are to demonstrate the accuracy of our new NATUS diagnostic method to determine the genetic health of the developing fetuses in a multiple gestation pregnancy from a maternal blood sample. The long term goal of this study will be the development of a method of minimally invasive prenatal diagnosis that has a higher sensitivity and lower false positive rate in the intended population (e.g. multiple gestation pregnancies) than any currently available screening tests. This will result in fewer unnecessary amniocenteses and CVS procedures, which are associated with a risk of miscarriage.