WHAT IS THE IMPORTANCE OF TISSUE TYPING IN DISEASES LIKE THALASSEMIA, HEMOPHILIA. ETC.? IS TISSUE TYPING POSSIBLE IN EMBRYOS?

Individuals transfer the genetic disorders to their offspring in various degrees. Therefore, determination of genetic disorders in couples and embryos is important in terms of having healthy children. Diagnoses of many genetic disorders are possible in our days as early as the embryonic stage with DNA analysis methods. The structure of the gene that causes a genetic disorder must be defined in order to diagnose a genetic disorder. Structures of many genes that cause disorders like Beta-thalassemia, Hemophilia, Cystic Fibrosis Sickle Cell Anemia, Muscular Dystrophies, and Fragile X Syndrome are now defined, and methods for their genetic diagnosis have been developed after many researches performed. In our center, genetic analyses are performed to show genetic defects on blood samples of mother, father, and affected children, if any. Following these analyses, the genetic structure causing certain disorders in the cells of the embryos obtained in in vitro fertilization programs, who are carriers of these disorders mentioned, can be defined with DNA analyses. As a result, it is possible to give birth to healthy babies by excluding the embryos with genetic disorders. Structures of many genes that cause disorders like Beta-thalassemia, Cystic Fibrosis Sickle Cell Anemia, Hemophilia, Muscular Dystrophies, and Fragile X Syndrome are now defined, and methods for their genetic diagnoses have been developed after many researches performed. Furthermore, with DNA sequencing methods, it is possible to perform HLA genotyping (tissue typing) simultaneously with the procedures performed to determine the healthy embryos, and to define the tissue type of the embryos in disorders like Beta-Thalassemia, Fanconi Anemia, and leukemia. Thus, embryos can be selected with a tissue type that matches that of an affected child in the family among the healthy embryos, for families with children with diseases like thalassemia or leukemia. Healthy pregnancies thus obtained can provide a chance for cure for the affected child by using the cord blood and bone marrow of the healthy baby. With this method, the family will be saved of the physical and psychological trauma of the termination of a pregnancy following a prenatal diagnosis procedure. Furthermore, pre-implantation genetic diagnosis is a very helpful technique; since it ensures having healthy babies and saves the troubles of affected individuals like diagnostic difficulties, high costs of therapies, and at the same time, ensures the chance of cure. The researches that are being carried out currently will provide for determining the genetic structures of many more disorders, and also provide for defining these disorders in embryos.