广州地区儿童α地中海贫血的发生率及缺失基因检测结果分析

目的调查广州地区儿童α地中海贫血(α地贫)的发生率及其常见缺失型基因的分布特征。方法对4990例广州地区儿童进行以全自动凝胶电泳为主的α地贫血液学检查,并利用以缺口PCR(gap—PCR)为原理的单管多重PCR方法对筛查出的其中103例患儿进行常见的三种缺失型基因诊断分析。结果在4990人中检出α地贫427人,发生率为8.56%,其中,H病68人,发生率为1.36%,占α地贫的17.53%,通过HbBarts诊断的α地贫128人,占α地贫的32.99%。进行基因分析的103例全部都是缺失型,其中东南亚缺失型(--SEA)占72.87%,右侧缺失型(-α3.7)占18.60%,左侧缺失型(-α4.2)占8.53%;具体基因型分布为:--SEA/αα70例,--SEA/-α3.719例,--SEA/-α4.2和α/-α3.7各5例,αα/-α4.2和-α4.2/-α4.2各2例。结论在α地贫高发区,应加强对儿童人群进行α地贫的血液学筛查和常见基因的诊断。

The incidence of α - thalassemia and the analysis of α - thalassemia gene deletion detection in children in Guangzhou region

Objective To investigate the incidence of α-thalassemia and the distribution of the main three types of α-thalassemia gene deletion in children in Guangzhou region.Methods Samples from 4990 children in Guangzhou region were detected for α -thalassemia by means of hematologic examinations such as fully automatic hemoglobin agarose gel electrophoresis mainly.Then 103 of the 427positive samples were diagnosed by means of “a single tube multiplex PCR based the gap PCR principle”.Results 427 samples were screened among the 4990 samples,which meant the incidence of α-thalassemia was 8.56%.Including that the incidence of Hb H disease was 1.36%(68 of 4990)and occupied 17.53%of the carriers(68 oF 427).There were 128 samples of 427(32.99%)were diagnosed by finding Hb Bart's in hemoglobin agaro se gel electrophoresis.All the 103 samples were identified as follows:70 cases were genotype--SEA/αα,19 were--SEA/-α~ 3.7,5 were--SEA/-α~ 4.2and αα/-α~ 3.7,respectively,2 were α α/-α~ 4.2and--α~ 4.2/-α~ 4.2,respectively,So the constituent of the type of gene deletions were as followsby calculated with chromosome:--SEA was 72.87%,-α~ 3.7was 18.60%and-α~ 4.2was 8.53%. Conclusion In the area with high risk of α-thalassemia, it is recommended that more attention should be paid to detect the carriers of α-thalassemia in childhood by hematologic screening and common genic diagnosis.