Application of mapping allele with resolved carrier status technology in preimplantation genetic testing

OBJECTIVE To assess the value of mapping allele with resolved carrier status (MaReCs) technology for the determination of balanced translocation carrier status for embryos. METHODS Blastocysts produced by 25 reciprocal translocation carriers and 15 Robertsonian translocation carriers were detected by MaReCs. After genetic counseling, transplantable blastocysts were selected. Amniocentesis was performed to check fetal chromosomes at 16 to 20 gestational weeks, and the consistency of amniocentesis and MaReCs was determined. RESULTS No significant difference was found in the normal rate for chromosome copy number variations (CNVs) in blastocysts between reciprocal translocation carriers and Robertsonian translocation carriers (28.6% vs. 32.0%, P> 0.05). For 12 (48%) reciprocal translocation carriers and 8 (32%) Robertsonian translocation carriers, the status of translocation carrier of embryos was successfully determined. The results of amniocentesis were consistent with that of MaReCs in all 11 pregnancies. CONCLUSION MaReCs is a reliable method to distinguish the translocation carrier status of embryos of balanced translocation carriers. It can help a certain proportion of balanced translocation carriers to select completely normal embryos while reduce transfer of embryo carrying a balanced translocation.