Active clinical trials for "Chromosome Disorders"

This double-blind, cross-over, randomized, controlled trial (RCT) has the aim of evaluating the effectiveness of a metabolic support therapy in two cohorts of patients with idiopathic Autism Spectrum Disorder or Phelan-McDermid syndrome, commonly associated with syndromic autism. Each patient will receive Q10 ubiquinol + Vit. E and B for 4 months and only Vit. E and B for 4 months in a double-blind, cross-over design. Primary outcome measures of efficacy include Vineland Adaptive Behavior Scales, Childhood Autism Rating Scale, Clinical Global Impression-Improvement and Visual Analog Scales; secondary outcome measures include several questionnaires and tests of autism, cognitive function, problem behaviors, quality of life, communication and comorbid disorders, as well as measures of oxidative stress.

The risk of abnormal chromosome and structure is much higher in twins than in singletons, and traditional early pregnancy screening strategy for single pregnancy is not suitable for twins. Based on our management experience of fetal medicine at twin pregnancy, and multi-center cooperation, the study will carry out the following clinical studies: to explore a suitable, early, noninvasive and accurate prenatal screening strategy for twin pregnancy. fetal chromosomal abnormalities

Abnormal chromosome number, or aneuploidy, is common in human embryos. It is responsible for more than half of all miscarriages, and it is the leading cause of congenital birth defects. Besides, it has been described that aneuploidy may also affect embryo implantation. Therefore, selecting embryos that have the best chance of implanting and growing into a healthy baby is one of the most important steps in the field of assisted reproduction. Recent advances in genetic technologies, such as Next-Generation Sequencing (NGS), have allowed aneuploidy to be detected with greater sensitivity. The application of this technique to trophectoderm biopsies, taken from embryos before transfer to the uterus, has provided insight into the clinical impact of chromosomal status. This process of screening embryos to make sure they have the right number of chromosomes and to look for any structural abnormalities in the chromosomes is called Preimplantation Genetic Testing for Aneuploidy (PGT-A). It requires specific equipment and trained personnel that will add costs and risks, so non-invasive techniques are sought as an alternative. These non-invasive procedures have been explored by some groups analyzing the spent culture medium where the embryo is cultured up to the time of transfer or freezing. In daily routine, this media is discarded after finishing the embryo culture, but it has been reported that contains traces of embryonic cell-free DNA (cfDNA) that can represent the genetic load of the embryo. However, at the moment there is a high variability in results across studies, with a percentage of concordant results between the media and the trophectoderm biopsy ranging from 3.5 to 85.7%. Thus, the main objective of this project is to validate a new non-invasive method for PGT-A (niPGT-A), based on improved collection and analysis of the culture media to achieve higher rates of sensitivity and specificity and to decrease the effect of some intrinsic difficulties such as low embryonic cfDNA input, mosaicism and maternal contamination.

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.

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.

The purpose of this study is to collect maternal blood samples from pregnant women carrying a fetus with a confirmed diagnosis of chromosomal abnormality or genetic disorder including microdeletions in order to further develop a non-invasive prenatal screening test based on fetal DNA isolated from maternal blood.