8757例地中海贫血基因诊断结果分析与研究

Analysis and research of 8757cases of thalassemia gene diagnosis

目的探讨桂林地区地中海贫血的携带率、基因型特征及构成比。方法所有研究对象均采用跨越断裂位点聚合酶链反应(Gap-PCR)以及反向斑点杂交法(reverse dot blot,RDB)技术对地中海贫血基因常见缺失型和点突变的基因型进行检查分析,观察地中海贫血基因型分布情况。结果 8757例送检样本中,地中海贫血基因阳性总检出率为20.3%(1782/8757),确诊的α地中海贫血为1189例,占66.7%(1189/1782),其中包括550例α地中海贫血1基因型,占46.2%(550/1189);550例α地中海贫血2基因型,占49.4%(588/1189);41例HbH病基因型,占3.4%(41/1189)。确诊的528例β地中海贫血,占30%(528/1782),在528例β地中海贫血患者中,其中β^(CD41-42)/β~N的基因型比例最高,为47.54%(251/528),其次为β^(CD17)/β~N占21.02%。在41例β复合α地中海贫血基因型中,以19例β复合α地中海贫血1(--^(SEA)/αα)基因型检出率最高,占46.43%(19/41),并且检出β双重杂合子β^(IVSⅡ-654)/β^(EM)复合-^(SEA)/-α^(3.7)、β^(CD41-42)/β^(IVS-Ⅱ-654)复合-α^(3.7)/αα各1例,所占比例均为2.44%(1/41)。结论研究桂林地区地中海贫血的基因分型特点对于本地区开展遗传咨询和产前诊断提供参考数据。

Objective To explore the characteristics of genotypes and carrying rate composition ratio of thalassemia of Guilin region. Method All the subjects examined and analyzed the genotypes of common deletions and point mutations of thalassemia gene by Gap-PCR and RDB（reverse dot blot） Distribution of thalassemia genotypes. Results Among the 875 7 samples tested, the positive rate of thalassemia gene was 20.3%（ 1782/8757）,and the number of confirmed α-thalassemia was 1 189（ 66.7 %,1189/17 82）, among them, 550 cases of α-thalassemia 1 genotype accounted for 46.2%（550/1189）, 550 cases of crthalassemia 2 genotype（49.4%, 588/1189）, 41 cases of HbH genotype（3.4%, 41/1189）.Among the 5 28 patients with β-thalassemia, accounting for 30%（528/1782） of whom were genotypes with the highest proportion of β^（CD41-42）/β^N（ 47. 54%） 251/528） followed by β^（CD17）/β^N accounting for21.02%. Among 41 cases diagnosed as β/α thalassemia,β/α thalassemia 1（-^（SEA）/αα） genotype had the highest detection rate（46.43%,19/41）,and 1 case of β double heterozygous β^（IVSⅡ-654）/β^（EM）/SEA/-α^（3.7）and β^（CD41-42）/β^（IVS-Ⅱ-654）/α^（3.7）/αα.,Accounting for 2. 44%（1/41） respectively. Conclusions Genotyping of thalassemia in Guilin area provides reference data for genetic counseling and prenatal diagnosis in this area.