Preimplantation diagnosis of the beta 1 integrin knockout mutation as a model for aneuploid gene testing

The autosomal beta 1 integrin knockout mouse mutation was selected as a mod el to experimentally determine preimplantation diagnosis test reliability f or autosomal gene deletions and duplications. In experiment 1, which analyz ed 198 individually disaggregated single blastomeres, the observed test fre quencies matched the mathematically predicted frequencies calculated from t he independently derived values of 90% normal allele amplification, 92% mut ant allele amplification, 4% alternate allele contamination, and 4% failure to transfer amplifiable target DNA into the PCR reaction mix. This experim ent correctly predicted a normal embryonic phenotype in 143 (99.3%) of the 144 phenotypically normal autosomal recessive results. Experiment 2 compare d single biopsied blastomere test results to test results on the remaining embryonic cells cultured 1 week until trophoblast outgrowth. Single biopsie d blastomere analysis correctly predicted a normal autosomal recessive phen otype in 87 (98%) of the 89 embryos that would have been selected for impla ntation. Experiment 3 compared the PCR results of two biopsied blastomeres tested independently to the PCR result from the remaining cultured blastome res to improve test reliability. Given that embryos would have been implant ed only when two normal results were obtained, 17 of 17 phenotypically norm al embryos would have been implanted from among the 44 embryos tested. Thes e experiment 3 results are consistent with the mathematical prediction that about 99.9% of embryos implanted with two unaffected biopsied blastomere r esults would have had a phenotypically normal genotype.