Preimplantation genetic diagnosis for β-thalassemia using whole genome amplification

Objective: To achieve pregnancy with unaffected embryo using in vitro fertilization and embryo transfer (IVF-ET) and preimplantation genetic diagnosis (PGD) for the couples at risk of having children with β-thalassemia. Methods A couple carrying different thalassemia mutations of codon 41/42 and codon IVS2 position 654 received standard IVF treatment and intracytoplasmic sperm injection, embryo biopsy, single cell polymerase chain reaction and DNA analyses, and only the unaffected or carrier embryos were transferred to uterus. Pregnancy confirmation, and prenatal diagnosis were done at 20 week's gestation. Results A total of 13 embryos were analyzed in the IVF cycle. PGD indicated that 2 were normal(18.1%), 3 were affected (27.3%), and 6 were carriers (54.5%); diagnosis was not possible in 2. Three embryos were transferred to uterus on the third day after oocyte retrieval. Ultrasonography showed twin pregnancy with one blighted ovum. The prenatal diagnoses revealed that both fetuses were unaffected, one normal baby and one carrier were born. Conclusion: These studies represent the successful application of PGD for β-thalassemia in China.