海南343名黎族小学生α-地中海贫血基因型调查

STUDY ON THE GENOTYPES OF α-THA-LASSEMIA IN 343 SCHOOLCHILDREN OF THE LI NATIONALITY INHAINAN

目的了解我国黎族群体α-地中海贫血的发生率及基因型的分布状况。方法343例EDTA抗凝末梢血样，分别采自海南省陵水县两个黎族居住地的在校小学生．chelex法提取DNA。按EBaysalandTHJHuisman检测a-地贫2基因的方法、WinichagoonPrance检测a-地贫1基因的方法和SupanFucharoen检测HbCS基因的方法进行样品分析，但聚合酶链反应的实验条件略有改变．扩增产物经琼脂糖凝胶电泳鉴定。结果343名黎族小学生正常（aa/aa）154例（44．85％），a-地贫1余台子（aa/－-）4例（1．17％）．a-地贯2突变的185例（53．94％），未检出HbCS基因。具有a-地贫2突变的个体检出五种基因型：（－a3.7aa）68例;（－a4.2/aa）70例；（－a3.7/－a3.7）17例；（－a4.2/－a4.2）9例;（－a3.7＞-a4.2）21例。结论中国黎族小学生a-地中海贫血发生率较高，绝大多数为缺失型a-地贫2。未检出非缺失型的HBCS基因。

Objective To study the distributionof α-thalassemia and its genotypes in the Li nationality community on China. Methods 343 EDTAAnticoagulant peripheral blood samples were collected from school children in 2 communities of theLi nationality in Lingshui County, HainanProvince. The DNA was extracted by chelexmethod. The samples were analyzed with themethods of E. Baysal and T. H. J. Huisman approach for α-thala-2 gene detection, WinichagoonPranee approach for α-thal-1 gene detection, andSupan Fucharoen approach for HbCS gene detection. The conditions for the PCR were modifiedand the amplified products were separated on agarose gel electrophoresis. Results Among the 343school children of the Li nationality, there were154 normal (αα/αα) cases (44. 85% ), 4 α-thal-1heterozygous (αα/ - - ) cases (1. 17%), 185 αthal-2 mutational cases (53.94%). No HbCSgenes were detected. Five genotypes were detectedamong the cases with α-thal-2 mutation cases: 68cases of-α3/αα, 70 cases of-α4.2/αα, 17 cases of.α3.7/-α3.7 9 cases of α4.2/α4.2, and 21 cases of α3.7/-α4.2 genotype. Conclusion There is a high incidence of α-thalassemia in the school children ofthe Li nationality in China and most of them belongto the deletion type of α-thal-2. No HbCS geneswere detected so far in our study.