Will K, Dörk T, Stuhrmann M, von der Hardt H, Ellemunter H, Tümmler B, Schmidtke J
Abteilung für Humangenetik, Medizinische Hochschule, Hannover, Germany.
Hum Mutat. 1995;5(3):210-20. doi: 10.1002/humu.1380050305.
The mutational effects at the mRNA level were investigated by RT-PCR analysis of nine different nonsense mutations (Q39X, E60X, R75X, G542X, L719X, Y1092X, R1162X, S1196X, W1282X) and one frameshift mutation (1078delT) within the CFTR gene. With the exception of mutation R1162X, reduced mRNA levels ranging from 30% to less than 5% of the wild type have been observed. In case of the R75X and E60X mutations, the mRNA reduction was accompanied by the appearance of atypical CFTR isoforms. Single exon 3 skipping, as well as joint exon 2 and 3 skipping, was observed in lymphocyte and nasal epithelial mRNA derived from R75X alleles. The analysis of mRNA transcribed from E60X alleles revealed skipping of exon 3 (lymphocytes and nasal epithelial cells) or skipping of exons 3 and 4 (nasal epithelial cells). With the exception of the E60X mutation, no obvious tissue-specific differences in the splicing pattern and ratios of mutation to wild-type transcripts were detected between lymphocytes and nasal epithelial cells. In addition to aberrant splicing, the reduction of transcripts is the most common effect of nonsense and frameshift mutations within the CFTR gene.
通过逆转录聚合酶链反应（RT-PCR）分析囊性纤维化跨膜传导调节因子（CFTR）基因内的9种不同无义突变（Q39X、E60X、R75X、G542X、L719X、Y1092X、R1162X、S1196X、W1282X）和1种移码突变（1078delT），研究了mRNA水平的突变效应。除R1162X突变外，观察到mRNA水平降低，范围为野生型的30%至不足5%。对于R75X和E60X突变，mRNA减少伴随着非典型CFTR异构体的出现。在源自R75X等位基因的淋巴细胞和鼻上皮细胞mRNA中观察到单外显子3跳跃以及外显子2和3联合跳跃。对源自E60X等位基因转录的mRNA分析显示，外显子3跳跃（淋巴细胞和鼻上皮细胞）或外显子3和4跳跃（鼻上皮细胞）。除E60X突变外，在淋巴细胞和鼻上皮细胞之间未检测到剪接模式以及突变型与野生型转录本比例的明显组织特异性差异。除了异常剪接外，转录本减少是CFTR基因内无义突变和移码突变最常见的效应。
