清远市城镇人群α-地中海贫血的分子流行病学调查

Molecular epidemiological investigation on α-thalassemia among the neonates in Qingyuan

目的:调查清远市α-地中海贫血(α-地贫)的基因携带率及基因型频率;探讨新生儿脐血血红蛋白(Hb)Bart's水平与α-地贫类型的关系。方法:应用琼脂凝胶电泳技术对2 432例新生儿脐血进行Hb定量分析,有Hb Bart's区带的样本进行基因诊断;同时对筛查阴性者也行基因检测。结果:2 432例新生儿脐血样本中,检出Hb Bart's阳性样本265例,其中基因确诊253例,包括6种基因型、279个α-地贫等位基因(人群基因携带率为11.47%)。Hb Bart's阴性的样品,检出22例静止型α-地贫基因。结论:清远市户籍人群α-地贫发生率较高,同时阐明了清远市户籍人群中的α-地贫的基因携带率、基因突变类型及其分布特征,为清远市进行遗传咨询和产前诊断提供了有价值的基础资料。

Objective ： To investigate the carrying rate of α- thalassemia gene and the frequencies of genotypes among the neonates in Qingyuau, explore the relationship between hemoglobin （Hb） Bart＇s level in umbilical cord blood of neonates and the types of α- thalassemia. Methods： Agarose gel electrophoresis was used to quantitatively analyze Hb level in umbilical cord blood of 2 432 neonates, gene diagnosis was performed among the samples with Hb Bartg zone, at the same time, the cases with negative result of screening underwent gene detection. Results： Among 2 432 neonatal umbilical cord blood samples, 265 cases were found with positive Hb Bart＇s result, and 253 cases were diagnosed definitely, 5 genotypes and 279 alleles （the carrying rate was 11.47% ） were included; among the cases with negative Hb Bart＇s result, 22 eases were found with silent α-thalassemia gene. Conclusion： The incidence rate of α-thalassemia among household population in Qingyuan is relatively high, the study illuminates the carrying rate of α-thalassemia gene, types of gene mutation and the distribution characteristics at the same time and provides valuable basic data for genetic counseling and prenatal diagnosis.