Preimplantation genetic diagnosis for carriers of thalassemia and chromosomal abnormality

Abstract

To provide preimplantation genetic diagnosis(PGD) for two couples carrying thalassemia mutations and chromosomal abnormalities. Couple 1 were both carriers of β 41/42 thalassemia mutations, while the husband has carried a reciprocal translocation with a karyotype of 46,XY,inv(9)(p11;q13),t(11;22)(q25;q13). Couple 2 were both carriers of α (-SEA) thalassemia mutation. Their chromosome karyotypes were both normal, but had two spontaneous abortions. The couples had received 1 and 3 blastocysts respectively through in vitro fertilization(IVF) cycles. Following the biopsy, the cells underwent whole genome amplification, and the amplified DNA from each embryo was subjected to genetic testing and a 23-chromosome single nucleotide polymorphism(SNP) microarray assay. The embryo of couple 1 was diagnosed as carrier of β 41/42 thalassemia with euploid chromosomes. The embryo was transferred and resulted in intrauterine pregnancy. Similarly, an embryo of couple 2 was verified as carrier of α (-SEA) thalassemia with euploid chromosomes. PGD for aneuploidy coupled with testing for single gene disorders via trophectoderm biopsy and whole genome amplification is feasible. The approach can attain diagnosis with minimal damage with sound clinical outcome.