Benson M D, Julien J, Liepnieks J, Zeldenrust S, Benson M D
Department of Medicine, Indiana University School of Medicine, Indianapolis.
J Med Genet. 1993 Feb;30(2):117-9. doi: 10.1136/jmg.30.2.117.
A transthyretin mutation was discovered in a French family with familial amyloidotic polyneuropathy originally described in 1983. The syndrome is of early onset (approximate age 35 to 40) with carpal tunnel syndrome. Death is from cardiac disease. By direct genomic DNA sequencing an A-->G mutation was found in the position corresponding to the first base of transthyretin codon 49. The predicted alanine for threonine substitution in the transthyretin protein was proven by amino acid sequencing of transthyretin isolated from the plasma of an affected subject. Since the DNA mutation does not result in the creation or abolition of a restriction endonuclease recognition site, a new DNA analysis technique was used in which site directed mutagenesis is used to create an RFLP when the introduced mutation is in proximity to the natural mutation. Using a 27 nucleotide mutagenesis primer in the PCR reaction, a new Bg1I site was created on amplification of the variant allele. Using this test, termed PCR-IMRA, four affected members of the family were shown to have the mutation.
在一个法国家庭中发现了转甲状腺素蛋白突变，该家庭患有1983年首次描述的家族性淀粉样多神经病。该综合征起病较早（约35至40岁），伴有腕管综合征。死因是心脏病。通过直接基因组DNA测序，在与转甲状腺素蛋白密码子49的第一个碱基相对应的位置发现了A→G突变。从一名患病受试者的血浆中分离出的转甲状腺素蛋白的氨基酸测序证实了转甲状腺素蛋白中预测的丙氨酸被苏氨酸替代。由于DNA突变不会导致限制性内切酶识别位点的产生或消除，因此使用了一种新的DNA分析技术，即当引入的突变靠近自然突变时，利用定点诱变来产生限制性片段长度多态性（RFLP）。在PCR反应中使用一个27个核苷酸的诱变引物，在变异等位基因扩增时产生了一个新的Bg1I位点。使用这种称为PCR-IMRA的检测方法，该家族的四名患病成员被证明携带该突变。
