Novel Metabolic Biomarker for Autism Spectrum Disorder

描述（由申请人提供）：在美国，自闭症谱系障碍（ASDs）影响着1/110的儿童，但医生还没有有效的实验室测试来证实临床诊断。该提案旨在开发一种快速可靠的代谢阵列来识别ASD患者。使用从Biolog （Hayward， CA）获得的表型微阵列板，我们已经能够证明，在色氨酸作为淋巴母细胞样细胞唯一能量来源的情况下，54/56 (96.4%)ASD患者的烟酰胺腺嘌呤二核苷酸（NADH）的产生与40例对照相比持续减少。提出的项目的第一个目标是通过使用定制的表型微阵列板的50名额外患者和50名额外对照组的队列来验证我们的初步发现。新的培养皿将允许我们每个培养皿测试12个个体，每个个体只使用16万个细胞。在初步研究的96个样本的基础上，提出的100个样本，在显著性水平为0.01的单侧t检验中，统计能力为95.6%。第二个目的是利用我们的分析来评估新鲜血液样本中色氨酸存在时NADH的产生。作为第一步，我们计划使用我们已经测试过的6名患者和6名对照组来复制在新鲜淋巴母细胞样细胞系中观察到的结果

DESCRIPTION (provided by applicant): Autism Spectrum Disorders (ASDs) affect 1/110 children in the United States, but physicians do not yet have an effective laboratory test which can confirm the clinical diagnosis. This proposal aims to develop a quick and reliable metabolic array to identify individuals with ASD. Using Phenotype Microarray plates obtained from Biolog (Hayward, CA), we have been able to show that Nicotinamide Adenine Dinucleotide, reduced form (NADH) production in the presence of tryptophan as only energy source in lymphoblastoid cells was consistently reduced in 54/56 (96.4%) patients with ASD when compared to 40 controls. The first aim of the proposed project is to validate our preliminary findings using a cohort of 50 additional patients and 50 additional controls employing customized Phenotype Microarray plates. The new plates will allow us to test 12 individuals per plate, using just 160,000 cells per individual. The proposed 100 samples, in addition to the 96 samples from the preliminary study, will give statistical power of 95.6% in a one- sided t-test at significance leve of 0.01. The second aim is to use our assay to evaluate the NADH production in the presence of tryptophan in fresh blood samples. As a first step, we plan to use 6 patients and 6 controls that we have already tested to replicate the results observed in lymphoblastoid cell lines in fresh white cells. This first stage will allow us to determine if we are able to observe the same low levels of NADH production in the presence of tryptophan in leukocytes as was observed in lymphoblasts. Next, we will test fresh blood samples from 12 patients with ASD and 12 controls. To reduce output variability, we will try to start the test at the same time for all the samples, coordinating the sampling of the 24 individuals. Finally, we will test 24 patient and 24 control blood samples from new individuals in a blinded fashion to establish the predictive power of this test in patients with ASD. For this last part of the experiment, we will test each sample as soon as it arrives at our laboratory. We will use a single row of 8 wells on the customized plates for each individual, covering the rest of the plate with aluminum foil, to preserve the other rows for future tests. If our preliminary findings in lymphoblasts are confirmed in leukocytes, we would be able to develop a reliable, easy to perform, inexpensive laboratory test which could provide a diagnosis in about 4-5 days. Such a test could represent the first biochemical screening test for ASDs. PUBLIC HEALTH RELEVANCE: The goal of this project is to develop a screening tool for Autism Spectrum Disorders (ASDs). In our preliminary study, we detected significantly lower levels of NADH generated in the presence of tryptophan in patients with ASD when compared to controls. We propose to utilize the same metabolic profiling approach using leukocytes from fresh blood samples to determine if ASDs can be quickly and reliably distinguished from controls.