Study of metabolic screening, diagnosis, evaluation of treatment, and molecular analysis for organic and fatty acid disorders

本研究对器质性和脂肪酸类遗传性代谢病的筛查、诊断、病程评估、分子生物学分析等方面进行了研究，取得了以下成果：1）有机酸类和脂肪酸类遗传性代谢病新筛查诊断支持系统的开发：a）通过使用两种方法分析羊水上清液，开发了产前诊断有机酸障碍的精确方法，GUMS和串联MS，这是非常简单和快速的; B）开发了β-氧化的酶促评价方法。2）Fast-GUMS法：建立了使用极窄色谱柱的Fast-GC/MS法。3）脂肪酸氧化障碍（FAOD）成纤维细胞的细胞功能：将来自FAODs患者如VLCAD缺陷（VLCADD）、MCAD缺陷（MCADD）、CPU缺陷和2型谷氨酸血症（GA 2）的细胞在高温条件下培养，结果表明，在一定条件下，中链脂肪酸的氧化被加速，而长链脂肪酸的氧化被抑制。提示FAOD患者在发热状态下有发生急性脑病的潜在风险。另一方面，降血脂药物苯扎贝特可改善FAOD细胞的代谢状况。4）日本FAOD的分子基础：在分子水平上分析了10多例日本VLCADD和GA 2患者。5）疾病的病因学研究及应用串联MS筛查新生儿的效果：日本与亚洲其他国家疾病的比例不同。通过新生儿筛查发现的患者之间的结局明显优于发病期后检测的结果。

Metabolic screening, diagnosis, evaluation of clinical course, and molecular analysis on organic and fatty acid disorders were studied, and the following achievements were obtained.1) Development of the diagnostic support systems for new screening for inherited metabolic disorders of organic and fatty acids: a) A precise method of prenatal diagnosis for organic acid disorders was developed by analysis of amniotic fluid supernatant using two methods, GUMS and Tandem MS, which is very simple and fast; b) The method of enzymatic evaluation of beta-oxidation was developed. The utility of the method was confirmed with analysis of cultured cells from several patients with FAODs.2) Fast-GUMS method: Fast-GC/MS method, using extremely narrow column was developed. The analytical time was cut down to 1/4 of the conventional GUMS using capillary column.3) Cell function of cultured fibroblasts from fatty acid oxidation disorders (FAOD): Cells from FAODs patients such as VLCAD deficiency (VLCADD), MCAD deficiency (MCADD), CPU deficiency and glutaric acidemia type 2 (GA2) were cultured in the condition of high temperature, and it was revealed that oxidation of medium chain fatty acids was accelerated, while that of longer chain fatty acids was inhibited. It suggested that FAOD patients potentially have a risk of acute encephalopathy in the febrile condition. On the other hand, metabolic condition of FAOD cells was improved by Bezafibrate, a hypolipidemic drug.4) Molecular basis of Japanese FAODs: Over 10 Japanese patients with VLCADD and GA2 were analyzed at the molecular levels. Genotypes of these diseases were heterogeneous in Japanese.5) Study of etiology of diseases and effect of newborn screening using tandem MS: It was suggested that he proportion of diseases between Japanese and the other Asian counties was different. Outcomes between patients detected by newborn screening was much better than those detected after onset stage.