Tassone F, Hagerman R J, Taylor A K, Hagerman P J
Department of Biological Chemistry, University of California, Davis, School of Medicine, One Shields Avenue, Davis, CA, USA.
J Med Genet. 2001 Jul;38(7):453-6. doi: 10.1136/jmg.38.7.453.
FMR1 mRNA levels were determined in peripheral blood leucocytes for 48 fragile X males with methylated, full mutation alleles that are resistant to cleavage by methylation sensitive enzymes. Using quantitative (fluorescence) RT-PCR, we observed that more than half of these males produce FMR1 mRNA, with some mRNA levels approaching those found in normal subjects. In none of the samples analysed was there any evidence of premutation alleles. These results suggest that the assumed relationship between enzyme resistance and FMR1 gene silencing may not be generally valid. Despite the presence of FMR1 mRNA in some subjects, no FMRP production was detected by either immunocytochemistry or western blotting. The low/absent FMRP levels are probably a reflection of a post-trancriptional effect such as a defect in translation.
在48名具有甲基化的、对甲基化敏感酶切割具有抗性的全突变等位基因的脆性X男性患者的外周血白细胞中测定了FMR1 mRNA水平。使用定量（荧光）逆转录聚合酶链反应，我们观察到超过一半的这些男性产生FMR1 mRNA，一些mRNA水平接近正常受试者中的水平。在所分析的样本中均未发现前突变等位基因的证据。这些结果表明，酶抗性与FMR1基因沉默之间的假定关系可能并不普遍有效。尽管在一些受试者中存在FMR1 mRNA，但通过免疫细胞化学或蛋白质印迹均未检测到FMRP的产生。低/无FMRP水平可能反映了转录后效应，如翻译缺陷。
