用等位基因特异性PCR进行β-地中海贫血产前基因诊断

目的:对两对有重型β-地中海贫血患儿家族史的夫妇进行产前基因诊断。方法:应用等位基因特异性聚合酶链反应(PCR)技术检测两对夫妇及其高风险胎儿的5种β-地中海贫血突变类型:CD41-42(-CTTT)缺失突变、IVSII654(C→T)突变、CD17(A→T)无义突变、TATA盒nt-28(A→G)突变和CD71-72(+A)移码突变。结果:家系1的父亲为TATA盒nt-28(A→G)/N杂合子,母亲为CD41-42(-CTTT)/N杂合子,胎儿正常;家系2的父亲为CD41-42(-CTTT)/N杂合子,母亲为CD71-72(+A)/N杂合子,胎儿为CD41-42(-CTTT)/CD71-72(+A)双重杂合子;上述2例胎儿出生及引产后的基因分析验证结果与产前基因诊断完全一致。结论:等位基因特异性PCR能准确地对β-地中海贫血高风险胎儿进行产前基因诊断,对预防重型β-地中海贫血患儿的出生具有重要意义。

PRENATAL GENE DIAGNOSIS OF β-THALASSEMIA BY POLYMERASE CHAIN REACTION OF ALLELIC GENE

Objective:To perform prenatal gene diagnosis on two couples who had family history of bearing children with severeβ-thalassemia.Method:the following five mutations were detected with specific PCR of allelic gene for two couples and their high risky fetus:CD41-42(-CTTT),IVSⅡ654(C→T),CD17(A→T),TATA box nt-28(A→G)and CD71-72(+A).Results:In one family,the father was a heterozygote of TATA box nt-28(A→G)/N,mother was a heterozygote of CD41-42(-CTTT)/N and the fetus was normal.In another family,the father was a heterozygote of CD41-42(-CTTT)/N,mother was a heterozygote of CD71-72(+A)/N and the fetus was a compound heterozygote of CD41-42(-CTTT))/CD71-72(+A).Conclusion:Specific PCR of allelic gene can be successfully applied to the prenatal gene diagnosis of high risky fetus withβ-thalassemia,and it has an important significance in prevention of the birth of severeβ-thalassemia fetus.