海南昌江县孕妇α-地中海贫血基因型与临床表型特点

The genotype and clinical phenotypic characteristics of α-thalassemia in pregnant women in Changjiang county of Hainan province

目的研究海南省昌江县α-地中海贫血基因类型分布特征。方法应用基因诊断技术对2 544例孕妇进行α-地中海贫血基因检测,并对检测结果进行分析。结果 2 544例孕妇共检出785例α-地中海贫血患者,基因携带率为30.86%,其中东南亚缺失型杂合子(αα/--SEA)85例(10.83%),右缺失型杂合子(-α3.7/αα)263例(33.50%),左缺失型杂合子(αα/-α4.2)254例(32.36%),右缺失型纯合子(-α3.7/-α3.7)32例(4.08%),左缺失型纯合子(-α4.2/-α4.2)37例(4.71%),左缺失型合并右缺失(-α3.7/-α4.2)90例(11.46%),双重缺失杂合子(HbH病)24例,其中:-α3.7/--SEA16例(2.04%),-α4.2/--SEA 8例(1.02%)。静止型α-地中海贫血患者517例,标准型244例,血红蛋白H(HbH)病24例。静止型、标准型和HbH病三种临床表型比例差异均有统计学意义(P<0.01)。与正常对照组比较,三种临床表型血液学型差异均有统计学意义(P<0.05),各组型别间比较差异也有统计学意义(P<0.05)。结论海南昌江县是α-地中海贫血的高发区,主要以左缺失(αα/-α4.2)和右缺失(-α3.7/αα)为主,其次为东南亚缺失(αα/--SEA),临床存在较多的静止型和轻型α-地贫患者,常规筛查中容易漏诊。

Objective To study the distribution characteristics of α-thalassemia genotypes in Changjiang county,Hainan province.Methods 2 544 pregnant women with α-thalassemia were tested by genetic diagnosis and the results were analyzed.Results 785 cases of α-thalassemia were detected in 2 544 pregnant women,with a prevalence of 30.86%;of which,85 cases(10.83%) were the Southeast Asia missing heterozygote(αα/--EA);263 cases(33.50%) were rightmissing heterozygotes(-α3.7/αα) and 254 cases(32.36%) were left-missing heterozygotes(αα/-α4.2);32 cases(4.08%)were right-missing homozygotes(-α3.7/-α3.7);37 cases(4.71%)were left-missing homozygotes(-α4.2/-αa4.2);90 cases(11.46%)were left missing type combined with right missing(-α3.7/-α4.2);24 cases were double missing heterozygous;of which,16(2.04%)were-α3.7/--SEA,and 8 cases(1.02%) were-α4.2/--SEA.517 patients with quiescent α-thalassemia,244 patients with standard type,24 patients with hemoglobin H(HbH) disease.Differences in the proportion of clinical phenotypes among quiescent,standard type and HbH diseases were statistically significant(P<0.01).Compared with the normal control group,there were statistically significant differences between the three clinical phenotype hematological types(P<0.05),there was also statistically significant difference between groups(P<0.05).Conclusion The Changjiang county was a high incidence area of α-thalassemia,mainly with left deletion(αα/-α4.2) and right deletion(-α3.7/αα),followed by the absence of αα/--SEA.There were more patients with static and mild α-thalassaemia,and it would be easily missed in routine screening.