Clincial study of prenatal genetic diagnosis of thalassemia from amniotic fluid and umbilical cord blood

Objective: To investigate the clinical value of prenata genetic diagnosis of alpha-thalassemia and beta-thalassemia.Methods: A single-tube multiplex-PCR assay and a PCR combined reverse dot blot(RDB) hybirdiation were used to detect the thalassemia gene in amniotic fluid or umbilical cord blood in 48 cases of risk fetuses whose parents both with alpha-thalassemia or beta-thalassemia heterozygote.Results: Of 48 fetuses with thalassemia risk,10 were normal and 38 cases of thalassemia,among which 14 cases were α-thalassemia and 24 cases were β-thalassemia including 1 accompanied with α-thalassemia.14 cases of fetuses with alpha -thalassemia detected 8 cases of——SEA/——SEA homozygote,2 cases of——SEA /αα,1 cases of leftward deletion type,2 cases of-α3.7/αα ard 1 case of ααT/αα.24 cases of fetuses for beta-thalassemia revealed 16 cases of CD41-42 heterozygote,2 cases of CD41-42 homozygote,3cases of-28(A-G),1 case of IVS-nt 654/ CD41-42 double heterozygote,1 case of-28(A-G)/CD71-72 double homozygote and 1 case of-α3.7/ CD41-42 double heterozygote.10 cases fetuses with severe thalassemia were induced abortion,1 cases died after birth.prenatal diagnoses of thalassemia in all fetues were confirmed after birth or induced abortion.Conclusion: Single-tube multiple-PCR assay and RDB hybridization in detection of amniotic fluid and umbilical cord blood can make rapid and accurate prenatal diagnosis of alpha-and beta-thalassemia.It has significant clinical value for preventing birth of child with severe thalassemia.