Karyomapping in Preimplantation Genetic Testing of Patients with Beta-thalassemia and Sickle Cell Anemia

Abstract

Aim Preimplantation genetic testing (PGT) has been introduced to prevent the transmission of inherited diseases to the offspring. Karyomapping is a universal linkage-based test that has been recently introduced to PGT in the clinical practice. It utilizes single nucleotide polymorphism genotyping of individual parents along with a known disease reference from a family member for identification of the parental origin of chromosomes and the disease status of the embryos being tested. The objectives of this study were to first validate Karyomapping technique on previously known beta globin (HBB) test sample results and then establish as a sole PGT method for HBB mutation identification in the future. Materials and Methods First, Karyomapping protocol was validated on a total of 30 samples with HBB mutation identified by conventional PGT techniques. Then, Karyomapping was used on 31 samples as the sole technique to identify HBB mutation status. ResultsWe found a high concordance (97%) between the Karyomapping and conventional PGT results. For five PGT cycles for HBB mutations and direct Karyomapping PGT four unaffected and chromosomal normal embryos were transferred resulting two pregnancies. Conclusion: Karyomapping technique can reliably detect HBB mutation in clinical cases without a prior test development in the clinical practice and prevents the transfer of aneuploidy embryos.