Why are familial amyloidotic neuropathy patients in Sweden hard to show clinical manifestations.

为了阐明家族性淀粉样多发性神经病（FAP）发病和进展的关键因素，我们的小组成员，如神经科医生，眼科医生和胃肠病学家进行了以下研究。在我们的调查中，共有15名医生访问了Umea，Atafetea，Pitea和Biske。1.瑞典和日本FAP患者的FAP表型和日常生活方式检查。2.饮料、河水和池塘沃茨中各种微量元素水平的测量。在瑞典FAP患者中，不仅多发性神经衰弱的发病，而且眼部表现也比日本患者晚20年，临床表现也比日本患者轻。在肌电图研究中，瑞典FAP患者的外周感觉神经轴突变化更明显。在微量元素研究中，饮料和河水、池塘沃茨中的Asn水平显著高于日本。然而，在体外淀粉样蛋白形成研究中，Asn显示对淀粉样蛋白形成无显著影响。使用瑞典和日本患者的DNA样本，进行单倍型研究。有趣的是，瑞典FAP患者的基因型与日本患者略有不同。根据生活方式研究，瑞典FAP患者的酸奶摄入量远高于日本FAP患者，这表明瑞典和日本FAP患者的肠道流量可能存在很大差异。这些研究为阐明FAP淀粉样蛋白的形成机制提供了线索。应在全球范围内进行更多的长期研究。

To elucidate the key factor(s) for the onset and progression of familial amyloiodtic polyneuropathy (FAP), the following inivestigations were performed by our group members, such as neurologists, ophthalmologists, and gastroenterologists. For our investigations, totally 15 doctors visited Umea, Skelfetea, Pitea, and Biske. 1. Examinations of phenotypes of FAP and life styles of thir daily life in Swedish and Japanese FAP patients. 2. Measurements of levels of various trace elements in drinks, river and pond waters. In Swedish FAP patients, not only the onset of polyneuroapthy, but also ocular manifestations were later by 20 years and clinical manifestations were milder than those in Japanese patients. In electric myographic studies, Swedish FAP patients showed severer axonal changes in the peripheral sensoly nerves. In trance elements study, Asn levels in drinks and river and pond waters were significantly higher than those in Japan. However, in vitro amyloid formation study, Asn showed no significant effect on amyloid formation. Using DNA samples of Swedish and Japanese patients, haplotype study were performed. Interestingly, the genotype of Swedish FAP patients was a little bit different from that of Japanese patients. According the life style studies, intake amount of yogurt in Swedish FAP patients were much more higher than that of Japanese FAP patients, suggesting that intestinal flowla may be quite different in Swedish and Japanese FAP patients. Such studies may give a clue for elucidating amyloid formation mechanism of FAP. More long term studies should be performed in the worldwide.