PS-1基因外显子5～9的突变研究

目的：筛查PS-1基因外显子5-9的突变，了解PS-1基因突变在中国人群中的分布情况及在中国人群阿尔茨海默病（AD）发病中可能产生的影响。方法：利用PCR-SSCP分析技术对120例正常体检人群PS-1基因外显子5-9进行突变筛查。结果：在这5个外显子中未发现任何突变，但在内含子9中第16位核苷酸处发现一种基因多态性位点，T／G基因型频率为65．8％，T／T基因型的频率为34．2％，未发现GiG基因型；等位基因T的频率为67．1％，等位基因G的频率为32．9％。结论：PS-1基因外显子5-9的突变频率较低，可能不是中国人群AD的主要危险因素：内含子9多态性与AD之间的关系还需进一步研究证实。

Study on the Mutations of PS-1 Gene Exon 5～9

Objective: To screen the mutations of PS-1 gene exon 5-9, discuss the distributing of PS-1 and evaluate its effects on the pathogenesis of AD in Chinese population. Methods: PS-1 gene exon 5-9 mutations of 120 normal cases were screened by PCR-SSCP. Results: No mutation was found in the 5 exons and a polymorphism was found in the intron 9 at nucleotide 16. Frequency of T/G genotype was 65.8% and that of T/T genotype was 34.2% and no G/G was found. The frequency of allele T was 67.1% and that of G was 32.9%. Conclusion: The mutation frequency of PS-1 gene is quite rare and it may not be the main risk for AD in Chinese population. More researches are need to be performed to confirm the relationship between the polymorphism of intron 9 and AD.