关键词: 乙型肝炎, 特征选择, 风险与预防模式, 单核苷酸多态性（SNP）

Abstract: As one of the severe diseases, HBV（Hepatitis B Virus） infection is seriously affecting human health. This kind of virus infection is the main reason that leads to chronic liver disease, cirrhosis and liver cancer. Due to the particularity of HBV replication and high variability characteristics, related studies have revealed that the HBV gene mutation is the basic reason of persistent HBV infection. In order to understand the genetic variation of HBV, the SNP detection from HBV sequences has been widely applied in the large number of research, the detected SNP loci may contain great clinical significance. However, currently, the SNP loci detection methods are restricted by some negative factors, such as high technical difficulty, high expense and so on. Therefore, to explore a computer-based method for SNP loci detection becomes a trend. In this paper, considering the characteristics of SNP loci of the HBV sequence, an method of SNP loci detection based on optimal risk and prevention pattern is proposed. The proposed method is first applied to detect the SNP site in the HBV sequence. Experimental results show that the method has not only effectively detected the SNP loci of the sequence on HBV X gene fragment and the pre-C gene fragment which have been reported, and has also found a new SNP loci. Different from the SNP loci detection with hardware, the proposed method has the advantages of simple operation, low cost, and it can be accepted by general laboratory and medical institutions.

Key words: Hepatitis B Virus, feature selection, optimal risk and preventive patterns, Single Nucleotide Polymophism（SNP）