国人DMD基因多态标记P-20的高频多态位点及其在RFLP分析中的应用价值

HIGH FREQUENCY OF THE MspI 2.2/1.8kb ALLELE OF P-20 IN CHINESE POPULATION AND ITS APPLICATION OF RFLP ANALYSIS

P-20探针位于DMD基因突变热点区,是DMD基因诊断最常用的多态标记。作者在分析21个DMD家系时,除检测到多态片段Msp I 6.0/3.5kb外,在全部受检者中还发现另一组高频多态位点Msp I 2.2/1.8kb,二组多态联合检出杂合子频率为0.7004,使P-20对DMD的RFLP分析能力提高近一倍。根据缺失类型进一步分析了P-20区的基因图谱。

P-20,located in the region of hot mutation of Dystrophingene,is a very useful DNA marker,which was used to test for RFLP inunrelated Chinese patients with Duchenne and Becker muscular dystrophy orX-linked mental retardation.In addition to polymorphism at the 6.0/3.5kbMsp I allele site,we found an independent and high frequency of polymor-phism at the 2.2/1.8kb site.The combined heterozygote rate of these twosites rose to 0.7004.This differs from the results found in other popu-lations.Finally,the gene mapping of P-20 region was deduced.