Preimplantation Genetic Diagnosis for a Patient with Robertsonian Translocation

OBJECTIVE:To investigate the feasibility and risk of preimplantation genetic diagnosis (PGD) for screening normal offspring of Robertsonian translocation carriers.METHODS:This case was clinically diagnosed as primary infertility for 6 years; the husband was found to have chromosome der (13;14) (q10;q10) and oligozoospermia. For the solution of the couple's problem, controlled ovarian hyperstimulation (COH) and intracytoplasmic sperm injection (ICSI) were performed to obtain embryos. The embryos were drilled in zona by acidified Tyrode's solution at 6-8 cell stage (day 3 post-fertilization) and a single blastomere was removed from each embryo. All blastomeres were analyzed by fluorescence in situ hybridization (FISH) using the double color probes LSI 13q labeled by SpectrumOrange and Tel 14q labeled by SpectrumGreen. The embryos biopsied were cultured at once and the normal ones selected were transferred the next day. Prenatal diagnostic techniques were used to detect the karyotype of fetus at 18 weeks of gestation.RESULTS:Unbalanced, normal or balanced, and unclear embryos were separated. The couple obtained 50a (4/8)normal or balanced,and 37.5a (3/8)unbalanced, and 12.5a (1/8) unclear embryos. A singleton pregnancy followed, and the karyotype of the fetus (46,XY) was detected by prenatal diagnostic techniques.CONCLUSION:PGD is useful for screening out unbalanced embryos and is very valuable for solving the reproductive problem of Robertsonian translocation carriers and for avoiding fetal beings with severe disorders.