Genetics: Preimplantation diagnosis of cystic fibrosis by simultaneous detection of the W1282X and {Delta}F508 mutations

W1282X (W) and F508 () are the two most common mutations ofthe cystic fibrosis Israeli population. Patients who are homozygotes(WW and ) as well as compound heterozygotes (W) present a severephenotype of the disease. In the present study, we have developeda polymerase chain reaction (PCR)-based method for the detectionof both mutations simultaneously in a single blastomere. Unfertilizedhuman oocytes and single polyspermic blastomeres were subjectedto a two-round PCR amplification: a first round of multiplexPCR followed by a second round of nested PCR, done seperatelyat each locus. Clear signals at both loci were obtained in 51%(47/65) of oocytes and 69% (24/35) of blastomeres. The genotypeof the single cell analysed was determined by endonuclease digestionof the W products and by heteroduplex formation of the F products.This diagnostic system will allow the identification of affectedembryos (WW, , W) as well as phenotypically normal carriers(W++), and therefore may be used for cystic fibrosis preimplantationdiagnosis in families who carry either or both mutations