目的提高苯丙氨酸羟化酶基因突变的检出效率，快速对苯丙酮尿症患儿进行产前诊断。方法采用双脱氧指纹（ｄｉｄｅｏｘｙｆｉｎｇｅｒｐｒｉｎｔｉｎｇ，ｄｄＦ）检测技术，ｄｄＦ法是将单链构象多态（ｓｉｎｇｌｅｓｔｒａｎｄｃｏｎ－ｆｏｒｍａｔｉｏｎｐｏｌｙｍｏｒｐｈｉｓｍ，ＳＳＣＰ）分析技术和双脱氧测序技术结合为一体的检测基因突变的方法，它能有效地检测基因突变而不受扩增片段长度的限制。用ｄｄＦ法鉴定了苯丙氨酸羟化酶基因上的突变Ｙ１６５Ｘ，Ｙ２０４Ｃ和Ｑ３５５Ｈ。结果有多条泳带不同于正常对照泳带。采用ＳＳＣＰ技术，也检测出突变Ｙ１６５Ｘ和Ｑ３５５Ｈ显示了不同于正常的泳带位移，而扩增片段较长的含突变Ｙ２０４Ｃ的样本却未显示异常泳带。结论ｄｄＦ检测技术对大片段基因的突变检测比ＳＳＣＰ法更为敏感，是检测基因突变切实可行的方法 Objective To improve the detection efficiency of phenylalanine hydroxylase gene mutations and to make prenatal diagnosis of children with phenylketonuria rapidly. Methods Dideoxy fingerprinting (ddF) detection was used. The ddF method is a combination of single strand conformation polymorphism (SSCP) analysis and dideoxy sequencing for the detection of gene mutations. It can effectively Mutations are detected without being limited by the length of the amplified fragment. The mutants Y165X, Y204C and Q355H of the phenylalanine hydroxylase gene were identified by the ddF method. As a result, there are multiple bands different from the normal control bands. Using the SSCP technique, mutations Y165X and Q355H were also shown to show differences from normal band shifts, whereas samples containing mutant Y204C with longer amplicons did not show abnormal bands. Conclusion ddF detection of gene mutation detection of large fragments more sensitive than the SSCP method is a practical method to detect gene mutations