佛山地区孕期夫妇地中海贫血筛查及基因诊断

Antenatal screening and genetic diagnosis of thalassemia among pregnant women and their husbands in Foshan City

目的调查佛山地区孕期夫妇及胎儿地中海贫血(地贫)的发生率、基因突变类型及构成比。方法对以MCV和MCH进行筛查地贫阳性者,采用高效液相色谱技术(HPLC)检测血红蛋白(Hb)组分,若HbA2>3.5%或HbF>2.0%者采用反向点杂交技术进行β地贫的基因检测,同时对所有地贫筛查阳性及α地贫东南亚缺失型基因携带者的配偶采用GAP-PCR进行α地贫检测,对夫妻双方均为同类型地贫基因携带者的高风险胎儿进行产前基因诊断。结果在5102例标本中检出地贫基因携带者600例,地贫总发生率为11.76%。其中α地贫391例,发生率为7.66%,β地贫209例,发生率为4.10%,α地贫复合β地贫27例,发生率为0.53%。在α地贫中,东南亚缺失型(--SEA/αα)占75.19%,左、右缺失型(αα/-α4.2和αα/-α3.7)占21.22%;β地贫中,β41-42占42.11%,β654次之,占30.62%,β17为10.53%和β-28为9.09%。夫妇为同一类地贫基因型的高风险胎儿98例,发生率1.92%。对98例产前基因诊断,结果正常胎儿23例;α地贫45例,β地贫30例。结论阐明佛山地区孕期夫妇携带α和β地贫基因的发生率、基因突变类型以及通过产前遗传咨询,有效控制重型地贫患儿的出生,对于实行优生优育,提高人口素质具有重大意义。

Aim To investigate the incidence rate,the types of gene mutation,and the constituent ratio of thalassemia among pregnant women and their husbands in Foshan. Methods There 5 102 couples were screened for thalassemia by MCV and MCH.The components of hematoglobin（Hb） of the positive samples were detected by HPLC.If HbA2 was over 3.5% or HbF exceeded 2.0%,the testing of β thalassemia gene would be processed.Simultaneously,all screening-positive samples and the spouse of carriers who were deficiency α-thalassemia of South-East Asia would be detected for α thalassemia.If the couples were the same types of thalassemia gene carriers by screening,then antenatal gene diagnosis would be performed for high-risk fetus screening. Results Totally 600 thalassemias cases were detected in 5 102 samples,in which α-thalassemia,β-thalassemia and α,β thalassemia were 391 cases（7.66%）,209 cases（4.1%） and 27 cases（0.5%）,respectively.The total incidence rate of thalassemia was 12.29%.Among α-thalassemia,the rate of deficiency thalassemia of South-East Asia（——SEA/αα） and was 75.19%,left right side was 21.22%.The gene frequency of four main types of β-thalassemia was 92.35%,including 42.11%（β41-42）,30.62%（β654）,10.53%（β17） and 9.09%（β-28）.The resultls of antenatal diagnosis of 98 fetus whose parents were the same type of thalassemia carriers showed that 23 cases were normal,45 were α-thalassemia（27 with——SEA/αα,3 with thalassemia of leaf right side,3 with HbH,12 with HbBart＇s fetal dropsy）,30 cases were β-thalassemia（23 with heterozygote,4 with double heterozygote,3 with homozygote）. Conclusion The incidence rate,the types of gene mutation,and the constituent ratio of thalassemia among pregnant couples in Foshan were elucidated.