家族性淀粉样变性多发性神经病(FAP-Ⅰ)型是由于在坐位30处甲硫氨酸取代缬氨酸后变异的转甲状腺蛋白(Variant Transthyretin VTTR)组成的淀粉样纤维在全身沉积所引起。基于这种异常,FAP-Ⅰ型能通过放射免疫试验RIA证明亚临床阶段患者血清中有VTTR的存在及通过PCR证明基因存在而做出诊断。以上述方法,作者验证了一日本FAP-Ⅰ型家系中3名同胞为VTTR-Met30纯合子(homozygosity),其中2例系晚发且病情缓慢进 The familial amyloidosis polyneuropathy (FAP-I) type is caused by systemic deposition of amyloid fibrils consisting of a Variant Transthyretin VTTR that mutates after methionine-substituted valine at position 30. [ Based on this abnormality, the FAP-I type can be diagnosed by radioimmunoassay (RIA) to demonstrate the presence of VTTR in the serum of patients in the subclinical phase and to confirm the presence of the gene by PCR. In the above method, the authors verified that three sibs of a Japanese FAP-I pedigree were VTTR-Met30 homozygosity, two of which were late-onset and slow to enter