地中海贫血羊水及脐血产前基因诊断的临床研究

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

目的：研究检测α-地中海贫血及β-地中海贫血在产前基因诊断中的临床应用价值。方法：对48例地中海贫血的风险胎儿的羊水（或脐血）应用单管多重PCR体系和反向点杂交法检测α-地中海贫血和β-地中海贫血基因诊断。结果：共有38例胎儿检测出携有地中海贫血。其中α-地贫14例，包括东南亚缺失型杂合子（--^SEA／αα）2例，东南亚缺失型纯合子（--^SEA／--^SEA）8例；左缺失型杂合子（-α^4,2／αα）1例，右缺失型杂合子（-α^3.7／αα）2例，非缺失型点突变（αα^T／αα）1例；β-地中海贫血24例，包括CD41～42杂合子16例，-28（A—G）杂合子3例，双重杂合子3例（IVS2nt654／CD41-42，-28（A—G）／CD71-72（＋A），-α^3.7／CD41-42）。其中10例重型地贫儿引产，1例重型地贫儿产后新生儿死亡。所有病例经引产或正常分娩后均留取脐带血作地贫基因诊断证实产前诊断。结论：应用单管多重PCR体系及反向点杂交法能快速、准确进行α和β-地中海贫血产前羊水基因检测，这对于有效预防重型地中海贫血胎儿出生具有重大临床意义。

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 -α^3.7/αα ard 1 case of αα^T/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 -α^3.7/CD41-42 double heterozygote. 10 cases fetuses with severe thalassemia were induced abortion, 1 fetues were confirmed after birth or induced abortion. bridization in detection of amniotic fluid and umbilical alpha-and beta-thalassemia. It has significant clinical cases died after birth, prenatal diagnoses of thalassemia in all Conclusion： Single-tube multiple-PCR assay and RDB hycord blood can make rapid and accurate prenatal diagnosis of value for preventing birth of child with severe thalassemia .