D1S111 and 33.4 Polymorphism as a Tool of Genetic Identity among Egyptians

Abstract

llogeneic stem cell transplantation is the treatment of choice for many haematological diseases. Post transplantation evaluation is conducted through assessment of the hematopoietic chimeric status. Successful allogeneic transplantation is associated with engraftment of donor cells in the recipient’s bone marrow, a condition known as complete chimerism (CC), while engraftment with coexistence of both donor and recipient derived haemopoeitic cells is called mixed chimerism (MC). Many methods have been used to characterize the state of chimerism after BMT to determine the success or failure of engraftment and to detect recurrence of the disease such as red blood cell phenotyping, immunoglobulin isotype analysis and cytogenetics to assess the chimeric state. Conventional cytogenetics for chimerism testing has largely been replaced by fluorescence in situ hybridization (FISH) technique in sex-mismatched transplants using Y chromosome -specific probes. Limitations of these techniques included limited degree of polymorphism, poor sensitivity and required a donor and recipient that are sex mismatched. A variety of DNA based techniques have been applied for chimerism analysis, including detection of restriction fragment length polymorphism (RFLP) and polymerase chain reaction (PCR) of Y chromosome or polymorphic genetic loci namely variable number of tandem repeats (VNTR) or short tandem repeats (STR).