RARE TRANSTHYRETIN MUTATION (ASP18GLU) ASSOCIATED WITH CARDIOMYOPATHY

这个子项目是利用由NIH/NCRR资助的中心拨款提供的资源的许多研究子项目之一。子项目和调查员(PI)可能从另一个NIH来源获得了主要资金，因此可能会出现在其他CRISE条目中。列出的机构是针对中心的，而不一定是针对调查员的机构。在一例经活检证实以心肌病为特征的淀粉样变性的中年男性中，发现了一种罕见的转甲状腺素(TTR)基因突变(Asp18Glu)。最初考虑的是更常见的轻链淀粉样变性(AL)，但血液学检测阴性促使对病理性TTR突变进行筛查。利用分子遗传学和生化技术相结合的方法，建立了家族性甲状腺激素型淀粉样变性的鉴别诊断。TTR基因外显子2、3和4的单链构象多态(SSCP)筛查表明存在非典型DNA。SSCP检测使用了一种新的非放射性、银染的微型细胞技术。DNA直接测序证实该突变为18号密码子第三碱基T-A颠换。限制性片段长度多态(RFLP)检测证实了这一结果。BUSM MS资源的质谱分析证实，先证者的血清中存在变异蛋白TTRAsp18Glu。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. The identification of a rare transthyretin (TTR) gene mutation (Asp18Glu) in a middle-aged male with biopsy proven amyloid disease featuring cardiomyopathy was achieved. The more commonly occurring light chain amyloidosis (AL) was initially considered, but negative hematologic testing prompted screening for a pathologic TTR mutation. A differential diagnosis of familial transthyretin type amyloidosis (ATTR) was established using a combination of molecular genetic and biochemical techniques. Single-strand conformation polymorphism (SSCP) screening of exons 2, 3 and 4 of the TTR gene indicated the presence of atypical DNA. SSCP testing was performed using a new non-radioactive, silver stained minigel technique. The genetic abnormality was identified by direct DNA sequence analysis as a T to A transversion at the third base position in codon 18. This result was confirmed by restriction fragment length polymorphism (RFLP) testing. The presence of the variant protein, TTR Asp18Glu, in serum from the proband was confirmed by mass spectrometric analysis at the BUSM MS Resource.