View clinical trials related to Chromosomal Abnormalities.
Filter by: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.
Optimise genetic screening of human embryos using higher resolution techniques
This study will examine blood or other tissue samples from patients with Fraser syndrome and patients with Fryns syndrome to try to identify the gene responsible for these diseases. Fraser syndrome is characterized by congenital abnormalities including cryptophthalmos (lack of eyelid formation), syndactyly (webbed fingers or toes) and abnormal genitalia. Patients may also have abnormalities of the nose, ears and larynx (voice box), cleft lip or palate, and kidney agenesis. Fryns syndrome is characterized by hernia through the diaphragm, cloudy cornea, coarse facial features, cleft lip or palate, abnormal fingers and toes, heart, kidney and brain malformations and hydrocephalus (accumulation of fluid around the brain). This protocol consists of laboratory study only; it does not involve patient care or patient counseling. Patients with Fraser syndrome or Fryns syndrome are eligible for this study. Parents and healthy siblings of patients will also be included for genetic study, and parents of children with undiagnosed multiple congenital anomalies syndromes will be included for comparison study. Participants will provide a blood sample (about 8 to 10 teaspoons from adults; 1 to 3 teaspoons from children) or sample of skin cells collected by swabbing the inner surface of the cheek. Some patients may undergo a skin biopsy, in which a small skin sample (about 1/8-inch in diameter) is surgically removed. The tissue samples will be used to obtain DNA (genetic material) for laboratory testing. A permanent cell line-a collection of cells grown in the laboratory from the original tissue specimen-will also be established to enable additional testing in the future.