Berg L P, Grundy C B, Thomas F, Millar D S, Green P J, Slomski R, Reiss J, Kakkar V V, Cooper D N
Charter Molecular Genetics Laboratory, Thrombosis Research Institute, London, United Kingdom.
Genomics. 1992 Aug;13(4):1359-61. doi: 10.1016/0888-7543(92)90070-9.
A single basepair substitution at conserved position -1 in the exon 3a donor splice site of the liver-expressed antithrombin III (AT3) gene was detected by PCR/direct sequencing in a patient with sporadic type 1 ATIII deficiency and recurrent venous thrombosis. The lesion, a heterozygous silent AAG----AAA transition at Lys 176 occurred de novo in the proposita. Ectopic transcript analysis of lymphocyte mRNA demonstrated the presence of an abnormally sized mRNA specific to the patient which was shown by cDNA sequencing to lack exon 3a. Oligonucleotide discriminant hybridization demonstrated the absence of any detectable transcript of normal length derived from the disease allele. These findings demonstrate the utility of ectopic transcript analysis in the characterization of defects of mRNA splicing.
通过聚合酶链反应/直接测序，在一名散发型1型抗凝血酶III（AT3）缺乏症且反复发生静脉血栓形成的患者中，检测到肝脏表达的抗凝血酶III（AT3）基因外显子3a供体剪接位点保守位置-1处的单个碱基对替换。该病变是在先证者中发生的杂合沉默AAG----AAA转换，位于第176位赖氨酸。淋巴细胞mRNA的异位转录本分析显示，患者存在异常大小的mRNA，cDNA测序表明该mRNA缺乏外显子3a。寡核苷酸鉴别杂交表明，未检测到来自疾病等位基因的任何正常长度转录本。这些发现证明了异位转录本分析在mRNA剪接缺陷特征化中的实用性。
