Almeida M R, Alves I L, Sakaki Y, Costa P P, Saraiva M J
Centro de Estudos de Paramiloidose, Instituto Nacional de Saúde, Portugal.
Hum Genet. 1990 Oct;85(6):623-6. doi: 10.1007/BF00193586.
Transthyretin methionine 30 (TTR Met 30), which is associated with familial amyloidotic polyneuropathy, originates in a single base substitution (A for G) in the second exon of the TTR gene. This autosomal dominant disease can be diagnosed by RFLP analysis of NsiI-digested DNA. The amplification of DNA by PCR improves the diagnosis method, making it suitable for prenatal diagnosis. Using PCR-amplified DNA, prenatal diagnosis of two at-risk fetuses was performed. Control Met 30 and normal DNA (either genomic or produced by site directed mutagenesis) were processed in parallel. The diagnosis was made by hybridization with allele-specific oligonucleotide probes, and later confirmed by screening of the mutant protein in the amniotic fluid and, when possible, in the sera from the newborns. TTR Met 30 was detected in the amniotic fluid of a positive fetus whose father was the carrier of the mutation. This indicates that the mutant protein is expressed very early in development.
与家族性淀粉样多神经病相关的转甲状腺素蛋白甲硫氨酸30（TTR Met 30）起源于TTR基因第二个外显子中的单个碱基替换（A替换为G）。这种常染色体显性疾病可通过对经NsiI消化的DNA进行限制性片段长度多态性（RFLP）分析来诊断。通过聚合酶链反应（PCR）扩增DNA改进了诊断方法，使其适用于产前诊断。使用PCR扩增的DNA对两个有患病风险的胎儿进行了产前诊断。同时对对照Met 30和正常DNA（基因组DNA或通过定点诱变产生的DNA）进行处理。通过与等位基因特异性寡核苷酸探针杂交进行诊断，随后通过检测羊水以及可能的情况下检测新生儿血清中的突变蛋白进行确认。在一名父亲为突变携带者的阳性胎儿的羊水中检测到了TTR Met 30。这表明突变蛋白在发育早期就已表达。
