Genes on the X chromosome are known to be responsible for more than 290 hereditary diseases. Nowadays, new advances has been made in management of x –linked disorders. The presence of cell free fetal DNA (cffDNA) in maternal plasma of pregnant women has provided the possibility of applying cffDNA in prenatal diagnosis as a non-invasive method, also the simple selection of embryo sex following IVF before uterine transfer can prevent the occurrence of affected offspring among couples at risk for these genetic disorders. Therefore in this study, the probability of detecting sequences on the human Y-chromosome in pregnant women has been evaluated to identify the gender of fetuses. Peripheral blood samples were obtained from 30 pregnant women with gestational age between 6th to 10th weeks and the fetal DNA was extracted from the plasma. Identification of SRY, DYS14 & DAZ sequences, which are not present in the maternal genome, was performed using Real-Time PCR. All the obtained results were compared with the actual gender of the newborns to calculate the test accuracy. Considerable 100% sensitivity and 100% specificity were obtained. Also our aim in this study was to develop a rapid method of pre implantation genetic diagnosis (PGD) using real-time polymerase chain reaction (PCR) for the sexing of human embryos, and to compare it to the fluorescence in-situ hybridization technique, considered to be the gold standard. It was possible to analyse 20 embryos, generating a total of 40 blastomeres (20 per technique). A rapid and safe method was developed in the present study for the sexual diagnosis of a single human cell (blastomere) using the emerging technology of real-time PCR. |
