Preimplantation diagnosis by fluorescence in situ hybridization using 13-,16-, 18-, 21-, 22-, X-, and Y-chromosome probes

Purpose: Our purpose was to select the proper chromosomes for preimplantati on diagnosis based on aneuploidy distribution in abortuses and to carry out a feasibility study of preimplantation diagnosis for embryos using multipl e-probe fluorescence in situ hybridization (FISH) on the selected chromosom es of biopsied blastomeres. Methods: After determining the frequency distribution of aneuploidy found i n abortuses, seven chromosomes were selected for FISH probes. Blastomeres w ere obtained from 33 abnormal or excess embryos. The chromosome complements of both the biopsied blastomeres and the remaining sibling blastomeres iii each embryo were determined by FISH and compared to evaluate their preimpl antation diagnostic potential, Results: Chromosomes (16, 22, X, Y) and (13, 18 21) were selected on the ba sis of the high aneuploid prevalence in abortuses for the former group and the presence of trisomy for the newborn for the latter: Thirty-six (72%) of 50 blastomeres gave signals to permit a diagnosis. Diagnoses made from bio psied blasotmeres were consistent with the diagnoses made from the remainin g sibling blastomeres in 18 embryos. Zn only 2 of 20 cases did the biopsied blastomere diagnosis and the embryo diagnosis not match. Conclusions: If FISH of biopsied blastomere was successful. a preimplantati on diagnosis could be made with 10% error.