RESUMEN
<p><b>OBJECTIVE</b>To investigate the clinical feasibility of cell-free fetal DNA (cffDNA)-based noninvasive prenatal diagnosis of β-thalassemia.</p><p><b>METHODS</b>Nine samples of amniotic fluid were obtained to detect the 8 common and 9 relatively rare mutation sites of β-thalassaemia in Guangdong Province. The maternal blood samples were also collected for extracting and purification of the cffDNA, and a duplex PCR was performed using 3 pairs of primers and the fetal β-globin genotype was analyzed by reverse dot-blot hybridization.</p><p><b>RESULTS</b>Among the 9 cases, 5 showed fetal genotypes of β-thalassemia inherited from the father by examination of the amniotic fluid, and 2 fetuses were identified to have β-thalassemia genes inherited from the father determined based on the cffDNA in the maternal blood.</p><p><b>CONCLUSIONS</b>The cffDNA-based noninvasive prenatal diagnosis is feasible for β-thalassemia, but the contamination of the maternal background DNA results in a low detection rate.</p>