OBJECTIVETo develop a primer-extension in combination with denaturing high-performance liquid chromatography (PE-DHPLC)-based assay for prenatal diagnosis of the five most common beta-thalassemia mutations in Chinese.

METHODSThe human beta-globin gene fragment was amplified by PCR, followed by a multiple PE reaction specific for each five mutations. Then the PE product mixtures were separated for genotyping of beta-globin gene mutations using fully-denaturing DHPLC analysis.

RESULTSIn a blind study, prenatal diagnosis was performed on thirty-six at-risk families for beta-thalassemia major. Reverse dot blot (RDB) analysis was used to validate each result, showing an accuracy rate of 100% for PE-DHPLC in a total of 108 samples tested. Overall, by PE-DHPLC analysis, the authors could identify the genotypes involving the five mutations and normal alleles corresponding to 94.4% (102/108) and actually make final decision for prenatal diagnosis covering 97.2% (35/36).

CONCLUSIONThe PE-DHPLC protocol can be a simple, rapid, and highly accurate assay in the prenatal detection of common beta-thalassemia mutations.