聚合酶链反应技术用于缺失型α－地中海贫血的产前诊断

Direct Genotyping and Antenatal Diagnosis of Deletional α-Thalassemia of the Southeast Asian Type by Pol ymerase Chain Reaction Technique

应用聚合酶链反应（ＰＣＲ）技术，对１０例高危妊娠者进行缺失型α－地中海贫血的产前诊断。结果：检测出胎儿水肿综合征患儿２例，杂合子４例，正常儿４例。扩增出现６３０ｂｐ左右的ＤＮＡ片段，说明有东南亚型缺失突变，为纯合于（－－／－－）。出现２２４ｂｐ的扩增片段则为正常人（αα／αα）。两种片段都出现则为杂合子（－－／αα）。提示ＰＣＲ技术用于α－地中海贫血的产前诊断，快速、准确。

bjective To study the gene of deletional α-thalassemia of the Southeast Asian type(SEA) and to perform the antenatal diagnosis. Metbods A new method of polymerase chain reaction technique using three primers bridging the breakpoints was carried out for carrier detection and antenatal diagnosis of deletional α-thalassemia of thesoutheast Asian type; A DNA fragment of about 630bp in size was arnplified in case of--SEA alleles,while a 2 24 bp fragment was amplified in samples without the deletion. Homozygotes,heterozygotes,and normal suUects could be clearly distinguished with the present method. Results We used this method in the genotyping and antenatal diagnosis of 10 high risk pregnan-cies of α-thalassemia,2 homozygotes, 4 heterozygotes, and 4 normal infants were found. Conclusion The present method is simple and rapid in detection of carriers and antenatal diagnosis of the α-thalassemia of southeast Asian type.