Use of parthenogenetic activation of human oocytes as an experimental model for evaluation of polar body based PGD assay performance

Purpose: To develop an experimental model to assess the feasibility of polar body preimplantation genetic diagnosis without requiring oocyte fertilization. Methods: First polar body was removed from donated oocytes and second polar body was biopsied after parthenogenetic activation. Molecular analysis on both polar bodies involved a fluorescent multiplex polymerase chain reaction of short-tandem repeat markers, closely linked to genes of interest. Main outcome measures were: allele segregation through polar bodies and haploid nucleus, recombination rates between alleles and frequency of Allele Drop Out. Results: Twenty-six out of 39 oocytes extruded a second polar body after activation. Ninety-two percent of the first polar bodies and 20 out of 26 (77%) second polar bodies were successfully amplified. Eighty percent of first polar bodies were heterozygous for CFTR and 55% for HBB. Analysis of second polar bodies predicted the genotype of the oocytes in case of heterozygous first polar body, and validated results in homozygous cases. Frequency of allele drop out was 4%. Conclusions: Our model confirms that polar body preimplantation genetic diagnosis for single gene disorders can be evaluated using parthenogenetic oocytes and offers an option to set up procedures without requiring oocyte fertilization.