An approach to preimplantation diagnosis of beta-thalassaemia

Using the polymerase chain reaction (PCR), it was possible to amplify a single copy fragment of the beta-globin gene from 2-32 human embryonic cells obtained from arrested preimplantation embryos. For the detection of beta-thalassaemia mutations, allele specific priming of the PCR using nested primers was employed using approximately 10 pg of DNA from individuals known to carry these mutations. This approach was successful in detecting the presence or absence of five Asian Indian beta-thalassaemia mutations that were selected for this study. In spite of meticulous precautions against contamination, false-positive amplification was observed, a problem that will have to be overcome before this approach can be used in clinical practice.