FRAXA与FRAXE位点的快速基因筛查

Ｘ染色体长臂末端罕见脆性位点Ａ与Ｅ与分别由一个可遗传的三核苷酸重复序列的延长所致二种脆 性位占在细胞遗传学水平难以区别。为了建立快速筛查ＦＲＡＸＡ与ＦＲＡＸＥ位点的基因诊断法，本文采用毛细管ＰＣＲ－序列胶银染显示法对正常人，脆性Ｘ综合征家系及智力儿童三组样本进行了检测，结果显示正常人群的Ｐ（ＣＧＧ）ｎ与Ｐ（ＧＣＣ）ｎ均呈多态分面

A rapid method of gene screening on FRAXA and FRAXE sites.

The fragile sites, FRAXA and FRAXE, which are located at the end of the long arm of X chromosome, are resulted from the expansion of a trinucleotide repeat sequence, P(CGG)n and P (GCC)n. It if difficult to distinguish FRAXA from FRAXE at the cytogenetic level. To establish a rapid detection method for the molecular diagnosis of FRAXA and FRAXE sites, we used rapid PCR with silver sequence gel stainning to detect three groups of samples from normal individuals, fragile X families and children with mental retardation. The results demonstrated that the P(CGG)n and P (GCC)n were polymorphic in normal persons and were inherited stably according to the Mendilian rule under normal conditions. The carriers of smaller premutation alleles could be detected by the above method. In this study we have set up a rapid, simple, cheap, safe and exact method for gene screening. This method could be used as the population screening of dynamic DNA mutation diseases.