Basic Research And Clinical Application Of Preimplantation Genetic Diagnosis

Preimplantation genetic diagnosis (PGD) is introduced as a method to analyze embryo hereditary substance before implantation, and to identify which embryo is normal and suitable to transfer. Thus it prevents genetic disorders. Compared with prenatal diagnosis, PGD can select unaffected embryos to transfer, thus avoiding selective and repeated abortion and moral conflict resulted from abortion. At present, PGD is performed widely as genetic screening in the couples with higher genetic risk such as genetic or chromosomal abnormality.Currentlly, the indications of PGD include (1) X-linked disorders, such as hemophilia; (2) chromosomal abnormality, including number and structural abnormality, such as aneuploidy and translocation; (3) single-gene defects, including of 30 kinds of single gene diseases such as thalassemia, cystic fibrosis.The basic procedure of PGD includes controlled ovarian hyperstimulation, oocyte pick-up (OPU), conventional IVF or intracytoplasmic sperm injection (ICSI), embryo culture to 6-10 cell-stage, detecting biopsied cell by FISH or PCR and transferring 2-3 unaffected embryos to uterus. From the view of broad...