经典型苯丙酮尿症苯丙氨酸羟化酶基因的新突变鉴定

目的研究经典型苯丙酮尿症(phenylketonuria, PKU)基因突变.方法应用聚合酶链反应,单链构象多态分析和DNA直接测序等技术,对内蒙古地区32个PKU家系苯丙氨酸羟化酶(phenylalanine hydroxylase, PAH)基因第3～12外显子进行了鉴定分析. 结果检出14种PAH基因点突变R243Q (12/64)、Y356X(6/64)、Y204C(5/64)、R261Q(2/64)、Y161S(2/64)、R252Q(1/64)、R111X(2/64)、D282G(1/64)、S303P(1/64)、G239D(1/64)、R413P(1/64)、IVS7nt+2(2/64)、IVS4nt+3(1/64)、IVS9nt+34(2/64),经检索国际PAH基因突变数据统计库(截至到2004年7月),确认IVS4nt+3(G>C)、IVS9nt+34(G>A)为国际首次发现的新突变,S303P(T>C) 、D282G(A>G)为国内首次报道的新突变.结论内蒙古人群苯丙氨酸羟化酶基因存在突变的多样性,R243Q、Y356X、Y204C是PAH基因的突变热点.

Identification of novel mutations in the phenylalanine hydroxylase gene of classical phenylketonuria

OBJECTIVE: To investigate the mutations of phenylalanine hydroxylase (PAH) gene in the cases of classical phenylketonuria (PKU). METHODS: The exons 3-12 of the PAH gene in 32 PKU patients from Inner Mongolia were studied by using PCR-single strand conformation polymorphism technique and DNA direct sequencing. RESULTS: Fourteen point mutations were identified. The frequencies of mutations were R243Q (12/64), Y356X (6/64), Y204C (5/64), R261Q (2/64), Y161S (2/64), R252Q (1/64), R111X (2/64), D282G (1/64), S303P (1/64), G239D (1/64), R413P (1/64), IVS7nt+2 (2/64), IVS4nt+3 (1/64) and IVS9nt+34 (2/64). Two novel mutations IVS4nt+3 (G>C) and IVS9nt+34 (G>A) were first found. The S303P (T>C) and D282G (A>G) were first documented in Chinese PAH gene. CONCLUSION: This study demonstrated the variety of the mutation type PAH gene of PKU in Inner Mongolia population, and confirmed that R243Q, Y356X, Y204C were the hot spots of PAH gene mutation.