目的报告地中海贫血伴染色体异常的夫妇,在滋养外胚层活检后同时进行地中海贫血基因以及染色体非整倍性检测的两个临床病例。方法两对地中海贫血携带伴染色体异常的夫妇,其中夫妇1双方为1341/42地中海贫血携带者,男方为46,XY,inv(9)(p11;q13),t(11;22)(q25;q13)的相互易位携带者;夫妇2双方为a-SEA地中海贫血携带者,双方染色体正常,但曾有两次自然流产史。经过常规体外受精周期,两对夫妇最终分别获得1个及3个囊胚。活检后的细胞经全基因组扩增后,分别采用PCR技术对地中海贫血基因进行检测,同时用单核苷酸微阵列技术检测23条染色体的非整倍性。结果夫妇1的胚胎诊断为β41/42地中海贫血杂合子,染色体正常,移植并成功妊娠;夫妇2的1个胚胎诊断为αSEA地中海贫血杂合子,染色体正常可以移植。结论滋养外胚层活检细胞经全基因组扩增后可以同时进行地中海贫血以及23条染色体非整倍性的检测。并且这种新的方法有助于这类复杂情况的患者在最小的损伤下获得诊断,达到更优的临床结局。
Objective To provide preimplantation genetic diagnosis(PGD) for two couples carrying thalassemia mutations and chromosomal abnormalities. Methods Couple 1 were both carriers of β41/42 thalassemia mutations, while the husband has carried a reciprocal translocation with a karyotype of 46,XY, inv(9) ( pl 1 ; q13), t (11 ; 22) (q25 ; q13). Couple 2 were both carriers of a-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 ceils 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. Results The embryo of couple 1 was diagnosed as carrier of t341/42 thalassemia with euploid chromosomes. The embryo was transferred and resulted in intrauterine pregnancy. Similarly, an embryo of couple 2 was verified as carrier of a-sEA thalassemia with euploid chromosomes. Conclusion 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.