Dworniczak B, Kalaydjieva L, Pankoke S, Aulehla-Scholz C, Allen G, Horst J
Institute of Human Genetics, WWU, Münster, Germany.
Hum Mutat. 1992;1(2):138-46. doi: 10.1002/humu.1380010209.
Complete sequence analysis of 194 human phenylalanine hydroxylase genes from PKU patients originating from West Germany and Bulgaria revealed 13 different mutations within exon 7 of the gene. Four of these mutations (T238P: ACT-->CCT; L242F:CTC-->TTC; R252G:CGG-->GGG; and 1043 delta 11: nt 1043-nt 1053 deleted) have so far not been described in the literature. Including these new mutations at least 21 different gene lesions and one sequence polymorphism exist for exon 7. Despite this large number unbiased calculation of the mutation frequency/exon size ratio does not provide conclusive evidence that exon 7 is a hot spot for disease causing mutations. Extensive screening during our experiments also failed to demonstrate the existence of excessive polymorphism in this part of the gene. It might therefore be speculated that the functional importance of the highly conserved exon 7 sequence accounts for the clustering of observed mutations which result in clinically manifest PKU. In addition we report our experience in regard to the resolution capacity of denaturing gradient gel electrophoresis (DGGE), a nonradioactive technique for the rapid screening of unknown mutations in exon 7.
对来自西德和保加利亚的苯丙酮尿症（PKU）患者的194个人苯丙氨酸羟化酶基因进行的完整序列分析显示，该基因第7外显子内有13种不同的突变。其中4种突变（T238P：ACT→CCT；L242F：CTC→TTC；R252G：CGG→GGG；以及1043del11：第1043位核苷酸至第1053位核苷酸缺失）迄今尚未见文献报道。包括这些新突变在内，第7外显子至少存在21种不同的基因损伤和1种序列多态性。尽管数量众多，但对突变频率/外显子大小比率进行的无偏计算并未提供确凿证据表明第7外显子是致病突变的热点。我们实验中的广泛筛查也未能证明该基因这一部分存在过多的多态性。因此可以推测，高度保守的第7外显子序列的功能重要性导致了观察到的突变聚集，这些突变会导致临床上表现出苯丙酮尿症。此外，我们报告了我们在变性梯度凝胶电泳（DGGE）分辨率方面的经验，DGGE是一种用于快速筛查第7外显子未知突变的非放射性技术。
