A study on the mutations at the phynylalanine hydroxylase gene among the Japanese population

目的：苯丙氨酸羟化酶基因位点至少有31个突变已被确定在不同种族人群。已知这些突变在这些种族人群中的分布存在显著差异。本研究旨在阐明日本苯丙酮尿症和高苯丙氨酸血症患者中苯丙氨酸羟化酶基因的突变。材料与方法：本研究纳入了3名苯丙酮尿症患者、1名高苯丙氨酸血症患者和2名健康人。经蛋白酶K消化后，用苯酚提取法从外周血白细胞或淋巴细胞中提取基因组DNA。用聚合酶链反应技术扩增苯丙氨酸羟化酶基因的第3和第5外显子。引物序列如前所述。结果：<553>在1例苯丙酮尿症患者的1个等位基因中发现了一个^ C-&gt;T突变（R111 Ter突变）。该患者和其他患者的另一个等位基因的突变尚未确定。评论：该突变已在中国苯丙酮尿症患者中确定，因此具有病因学意义。对该患者和另一患者的另一等位基因突变的分析正在进行中。

Objectives : At least thirty-one mutations at the phenylalanine hydroxylase gene locus have been identified among various ethnic populations. Significant differences in the distribution of such mutations are known among such ethnic populations. This project was designed to elucidate mutations at the phenylalanine hydroxylase gene among the Japanese phenylketonuric and hyperphenylalaninemic patients.Materials and Methods : Three phenylketonurics, one hyperphenylalaninemic patient and two healthy individuals were enrolled in this study. Genomic DNA was extracted from peripheral leukocytes or lymphocytes after proteinase K digestion by phenol extraction. Exons 3 and 5 of the phenylalanine hydroxylase gene were amplified by the polymerase chain reaction technique with the DNA specimens extracted from these individuals as templates. Sequences of primers were as previously described. The amplified exons were cloned and subjected to sequencing by a dideoxy technique.Results : A ^<553>C->T mutation (R111Ter mutation) was found in one allele of one of the phenylketonurics. The mutations at the other allele of this patient and in the other patients have not been identified.Comments : This mutation have been identified among the Chinese phenylketonuric patients, and accordingly is of etiological significance. Analysis of mutations in the other allele of this patient and in the other patient are now in progress.