OPTIMAL POLYMERASE CHAIN-REACTION AMPLIFICATION FOR PREIMPLANTATION DIAGNOSIS IN CYSTIC-FIBROSIS (DELTA-F508)

Objective-To evaluate direct polymerase chain reaction amplification o f mutation on single embryo cells for the routine preimplantation diag nosis of cystic fibrosis. Design-Direct polymerase chain reaction ampl ification of mutation was performed to identify the cystic fibrosis De lta F508 mutation in human blood DNA, single lymphocytes, embryos, and embryo cells obtained by biopsy. Preimplantation diagnosis was perfor med for a couple who were heterozygous carriers of the Delta F508 muta tion. Setting-Laboratory for preimplantation diagnosis in a reproducti ve medicine unit. Main outcome measure-Correct diagnosis of homozygous normal, heterozygous, and homozygous abnormal DNA of the cystic fibro sis Delta F508 mutation. Results-45 blood samples (18 homozygous norma l, 17 heterozygous, and 10 homozygous abnormal) and 204 single lymphoc ytes from known sources showed 100% amplification and were diagnosed c orrectly. 17 human embryos and 52 normal nucleated embryo cells obtain ed by single cell embryo biopsy also showed 100% amplification. After a miscarriage of the initial pregnancy (diagnosed at preimplantation t o be homozygous normal) in the heterozygous carrier couple, fetal tiss ue was confirmed to be homozygous normal. Conclusion-Direct polymerase chain reaction amplification of mutation is a simple, fast, reliable test for the common cystic fibrosis mutation (Delta F508) in blood DNA and single cells and should be applicable to routine programmes of ge neral screening, maternal blood examination, and preimplantation diagn osis.