2005年至2011年间产前诊断重型及中间型α-地中海贫血的相关分析

Analysis on the prenatal diagnosis for the pravis type and intermediate type α-thalassemia from year 2005 to 2011.

目的分析2005-2011年间在我院产前诊断为重型α-地中海贫血、中间型α-地贫血红蛋白H病胎儿检出情况。方法对夫妇双方经地贫基因检测诊断为α-地贫基因携带的妊娠妇女,且双方为可能生育重型α-地贫和/或血红蛋白H病患儿的基因组合进行产前地贫基因诊断。主要检测三种缺失:--SEA、-α3.7、-α4.2以及罕见的--THAI缺失;三种点突变:ααCS、ααQS和ααWS点突变类型。结果双亲可能生育重型α-地贫患儿风险的组合有86例次,检出重型α-地贫24例,理论上子代发生频率为25%的实际检出率为27.9%。双亲可能生育血红蛋白H病患儿风险的组合78例次,检出中间型α-地贫血红蛋白H病30例,理论上子代发生频率为25%的组合实际检出率为32.8%;理论上子代发生频率为50%的基因组合实际检出率64.3%。结论根据双亲基因组合,子代重型α-地贫和血红蛋白H病实际检出率均略高于理论发生频率的检出率,但统计学无显著性差异(P>0.05),符合常染色体隐性遗传病的遗传模式。

Objective： To analysis the detection of gravis type α-thalassemia and intermediate type α-thalassemia（Hemoglobin H disease）using prenatal diagnosis from year 2005 to 2011 in our Hospital.Methods： We will take prenatal diagnosis for the pregnant woman who she and her husband are both the carrier of α-thalassemia gene,and have high risk fetus with gravis type α-thalassemia or Hemoglobin H disease.We detected three deletion mutations mainly,there are——^SEA,-α^3.7,-α^4.2 and infrequent——THAI deletions,three point mutations include ααCS,ααQS,and ααWS mutations.Result： 86 cases that had gravis type α-thalassemia risk were accepted prenatal diagnosis and 24 cases had been detected,the detection rate is 27.9%,but the incidence rate of progeny is 25% in abstracto.78 cases that had Hemoglobin H disease risk were also accepted prenatal diagnosis and 30 cases had been detected,we compared the theoretical incidence rate in progeny with the practical detection rate,25% pair with 32.8% and 50% pair with 64.3%.Conclusion： Base on the parent＇s genotype,the practical detected rate of gravis α-thalassemia and Hemoglobin H disease in the progeny is higher than the theoretical incidence rate,but the difference is insignificant,the genetic characteristics is consistent with autosomal recessive inheritance.