Rapid diagnosis of beta-thalassaemia by mutagenically separated polymerase chain reaction (MS-PCR) and its application to prenatal diagnosis.

We have developed a rapid and simple PCR-based method which is modified from the mutagenically separated polymerase chain reaction (MS-PCR) to detect the molecular defects of beta-thalassaemia. We can use this technique to amplify normal and mutant alleles of the beta-globin gene in the same reaction tube, using different-sized allele-specific primers. This mutagenesis separates the amplification reactions of alleles performed in the same tube. Subsequent gel electrophoresis shows at least one of the two allelic products at the same locus or at least two of the several allelic products at different loci. Therefore, in addition to simple handling, MS-PCR provides a within-assay quality control for the exclusion of false negative results. The five most common mutations of beta-thalassaemia and haemoglobin E which occur in the Taiwanese population were tested, and 14 prenatal samples were checked with accurate results. This method is simple, rapid and accurate, and can be used routinely in prenatal diagnosis. The principle used here can also be applied to other genetic diseases.