孕妇血浆胎儿DNA的父源性α地中海贫血产前基因诊断

Prenatal gene diagnosis of paternally inherited α-thalassemia by detecting fetal DNA in maternal plasma

目的检测孕妇血浆胎儿 DNA 的父源性东南亚缺失型α地中海贫血1(SEAα地贫1)基因突变,进行无创伤性产前基因诊断。方法应用荧光聚合酶链反应(PCR)和基因扫描方法分析10例孕妇血浆胎儿 DNA 的父源性 SEAα地贫1基因突变及短串联重复序列(STR);同时以常规的绒毛、羊水或脐血胎儿 DNA 的基因诊断结果作对照。结果 10例孕妇血浆胎儿 DNA 均检测到父源性STR 等位基因。有4例检出父源性 SEAα地贫1基因突变;6例未检出父源性 SEAα地贫1基因突变,与常规的绒毛、羊水或脐血胎儿 DNA 的产前基因诊断结果一致。结论应用荧光 PCR 和基因扫描方法检测孕妇血浆胎儿 DNA 的父源性 SEAα地贫1基因突变,可排除血红蛋白 H 病胎儿。

Objective To evaluate the value of diagnosis of α-thalassemia by analyzing fetal DNA in maternal plasma. Methods Ten families were screened, the husbands being alphathalassemia Southeast Asia deletion（ SEA α-thalassemia-1 ）heterezygotes and the pregnant women being α-thalassemia-2 heterezygotes. Fluorescent polymerase chain reaction （PCR） and gene scanning were used to detect the paternally inherited genotypes of SEA α-thalassemia-1 gene mutation and short tandem repeats （STRs） in the maternal plasma fetal DNA. The results were compared to those of conventional prenatal diagnosis of fetal DNA in amniotic fluid, chorionic villus or cord blood. Results Paternally derived STR genotypes were detected in all specimens of plasma fetal DNA, Paternally inherited SEA α-thalassemia-1 gene mutation was detected in 4 cases, while the other 6 cases did not inherit the paternal mutation. The results were completely concordant with those of the conventional prenatal diagnosis. Conclusion Noninvasive prenatal diagnostic method, the technique using fluorescent PCR and gene scanning to detect the fetal DNA and paternally inherited SEA α-thalassemia-1 gene mutation in maternal plasma helps exclude the fetuses with hemoglobin H diseases.