GLUTARIC ACIDEMIA--MOLECULAR, BIOCHEMICAL, AND CHEMICAL HETEROGENEITY

谷氨酸血症（GAI）是一种人类先天性赖氨酸和色氨酸缺陷 氧化导致基底神经节变性和进行性的 儿童运动障碍。 死亡通常发生在第一次 十年 这种情况是由于缺乏戊二酰-CoA脱氢酶 GCDH是一种含有FAD的线粒体酶， 将戊二酰辅酶A脱羧为巴豆酰辅酶A和CO2。 我们一直在研究 这种疾病已经持续了近20年，是第一个描述这种疾病的人。 疾病和表征其有机酸尿，神经病理学， 酶缺陷 我们克隆并表达了编码人GCDH的cDNA， 确定了导致GAI的几种突变，目的是学习 这些突变与病理生理学和临床异质性的关系， 以及正常和突变酶的催化途径。 具体目标 本资助期旨在（a）描述导致GAI的GCDH突变，（B） 将这些突变与表达的 酶来开发人GCDH的详细结构-功能图，以及 检查表型和GCDH基因型之间的关系， 关于导致临床异质性的因素的可检验假设。 在这方面，具体目标（c）审查了假设t， 具有特异剪接位点的GCDH转录物的差异加工 突变是导致人群临床异质性的原因， 所有患者都是该突变等位基因的纯合型。 拟采用的方法 包括GCDH外显子单链构象多态性分析， 突变GCDH在大肠杆菌中的表达，正常GCDH的光谱和动力学研究 GCDH突变型及GAI患者成纤维细胞mRNA的RT-PCR检测。

Glutaric acidemia (GAI) is a human inborn error of lysine and tryptophan oxidation which causes degeneration of the basal ganglia and a progressive movement disorder in childhood. Death usually occurs during the first decade. The condition is due to deficiency of glutaryl-C0A dehydrogenase (GCDH), an FAD- containing mitochondrial enzyme that oxidatively decarboxylates glutaryl-CoA to crotonyl-CoA and CO2. We have been studying this disorder for almost twenty years, being the first to describe the disease and to characterize its organic aciduria, neuropathology, and enzyme defect. We have cloned and expressed cDNA encoding human GCDH and identified several mutations that cause GAI, with the objective of learning how these mutations relate to pathophysiology and clinical heterogeneity, and the catalytic pathways of normal and mutant enzymes. Specific aims for this funding period are to (a) delineate GCDH mutations that cause GAI, (b) correlate these mutations with functional abnormalities in the expressed enzyme to develop a detailed structure-function map of human GCDH, and examine the relations between phenotype and GCDH genotype to develop testable hypotheses about factors contributing to clinical heterogeneity. In this context, specific aim (c) examines the hypothesis t hat differential processing of GCDH transcripts with a specific splice site mutation is responsible for clinical heterogeneity in a population in which all patients are homozygous for this mutant allele. Methods to be employed include single strand conformation polymorphism analysis of GCDH exons, expression of mutant GCDH in E coli, spectral and kinetic studies of normal and mutant GCDH, and RT-PCR of fibroblast mRNA in GAI patients.