百色市地中海贫血筛查阳性夫妇的基因分析

Genetic analysis of couples with positive results in thalassemia screening in Baise

目的通过揭示百色市地中海贫血筛查双阳夫妇的基因诊断结果,为地贫遗传咨询提供参考。方法对2010年1月至2011年12月转诊至某院地贫产前诊断中心的450对地贫筛查双阳夫妇进行基因分析并计算高危地贫夫妇的比例及产前诊断结果。结果本组检测900条染色体,其中α地贫共检出243个等位基因突变,频率为27.0%;β地贫共检出144个基因突变,频率为16.0%;夫妇基因检测结果:450对夫妇双方基因检测结果显示,20.0%夫妇为不同类型的基因携带者/患者;43.0%夫妇双方为相同类型地贫基因携带者/患者,其中高危地贫夫妇占85.6%;仅一方为地贫基因携带者夫妇占26.0%;夫妇双方基因检测正常者占11.0%。有80.1%孕产妇进行产前诊断,其中检出正常胎儿占27.8%、重型/中间型(α地贫、β地贫或α复合β地贫等)地贫胎儿占30.1%。共避免了33例重型/中间型患儿的出生。结论百色市地贫筛查双阳夫妇中高危地贫夫妇占相当大的比例,开展大规模的人群筛查、基因确诊实验、遗传咨询和高危地贫胎儿的产前诊断是控制重型地贫儿出生的最佳途径。

Objective To provide reference for thalassaemia genetic counseling by revealing the genetic diagnosis of couples whose thalassaemia screening were both positive in Baise district. Methods 450 couples with positive results in thalassaemia screening, who were transferred to a prenatal diagnositic center for thalassemia from January, 2010 to December, 2011, were given genetic analysis. The proportion and prenatal diagnostic results of high risk cou- ples with thalassemia were calculated. Results Among 900 detected chromosomes, 243 allelicmutants were found in a thalassemia with a frequency of 27. 0% and 144 allelicmutants were found in 13 thalassemia with a frequency of 16.0%. The genetic testing results showed that within the 450 couples, 20% of couples were carriers or patients of different types of thalassemia and 43% of couples were carriers or patients of the same type of thalassemia,of which high risk couples with thalassemia covered 85.6 %. 26 % of all the couples had only one partner as carriers of thalassemia. 11% of all the couples were proved healthy in the genetic detection. 80.1~ of pregnant women went for prenatal diagnosis. 27.8% of them had healthy fetus and 30. 1%had fetus with thalassemia major or thalassemia intermedia （α-thalassemia,β-thalassemia or a-combined with β-thalassemia）. 33 fetus with thalassemia major or thalassemia inter- media were avoided. Conclusion High risk couples with thalassemia accounted for a considerable proportion in couples who got positive results in thalassemia screening in Baise district. Thus, to have large scale of population screening, genetic diagnosis experiment, genetic counseling and prenatal diagnosis for high risk thalassemia fetus are the best ways to avoid fetus with thalassemia major to come to birth.