分别携带β珠蛋白基因CD41—42（-TCTT）和CD43（G→T）突变夫妇的产前诊断结果分析

Analysis of a mistake occurring during prenatal diagnosis of two couples respectively carrying CD41-42 （--TCTT） and CD43 （G→T）mutations of the β hemoglobin gene

目的为两对双方分别携带β珠蛋白基因CD41-42（-TCTT）和CD43（G→T）杂合突变的夫妇提供产前诊断，明确其胎儿的基因型。方法应用反向斑点杂交法（两种试剂盒）、多色探针熔解曲线法和DNA序列分析法同时检测β珠蛋白基因的突变。结果家系1胎儿3种方法的检测结果均显示其为CD43（G→T）突变杂合子；家系2胎儿多色探针熔解曲线结果和DNA序列分析结果均提示为CD41—42（-TCTT）和CD43（G→T）突变双重杂合子，而反向斑点杂交法两种试剂盒产生了不一致的结果，一种为CD4142（-TcTT）和CD43（G→T）突变双重杂合子，而另一种为CD41—42（-TCTT）突变纯合子。结论对携带β珠蛋白基因CD41—42（-TCTT）和CD43（G→T）突变的夫妇进行产前诊断应采用其他可避免误诊的手段，如直接测序等。

Objective To provide prenatal heterozygous CD41-42 （--TCTT） and CD43 （G→T） mutations were simultaneously detected with reverse diagnosis for two couples who respectively carried mutations of the ~ hemoglobin gene. Methods The dot blot （two diagnostic kits）, multi-color melting curve analysis and sequencing analysis. Results The fetus of family 1 was shown to be heterozygous for CD43 （G→T） by the three methods, while the fetus of family 2 was shown to be double heterozygous for CD41-42 （--TCTT） and CD43 （G→T） by multi-color melting curve analysis and sequencing analysis. The two diagnostic kits yielded different results by reverse dot blot, one as double heterozygous for CD41-42 （--TCTT） and CD43 （G→T）, and another as homozygous for CD41-42 （--TCTT）. Conclusion For prenatal diagnosis of couples carrying mutations of hemoglobin gene such as CD41-42 （-- TCTT） and CD43 （G→T）, other methods such as Sanger sequencing should be used in order to avoid misdiagnosis.