Newborn screening for PKU and BH4 responsiveness

新生儿 PKU 和 BH4 反应性筛查

基本信息

批准号：
7329097
负责人：
Steven F Dobrowolski
金额：
$ 37.29万
依托单位：
BIOFIRE DEFENSE, LLC.
依托单位国家：
美国
项目类别：
财政年份：
2006
资助国家：
美国
起止时间：
2006-05-15 至 2008-11-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/7329097
关键词：
Address Affect Biological Assay Bion Blood Blood specimen Brain Injuries Cataloging Catalogs Classical phenylketonuria Code DNA DNA Sequence Analysis Data Defect Diagnostic Diet Disease Early identification Effectiveness Emerging Technologies Enzymes Frequencies Functional disorder Genes Genetic Polymorphism Goals Hand Hospitals Individual Introns Lead Measures Medical Messenger RNA Metabolic Metabolic Diseases Metabolism Methods Mutation Neonatal Screening Newborn Infant Patients Phenylalanine Phenylalanine Hydroxylase Physiological Play Polymerase Chain Reaction Population Process Purpose Reagent Research Research Personnel Resolution Retrospective Studies Role Scanning Screening Result Secondary to Site Source Specimen Technology Testing Tyrosine Withdrawal base cost cost effective day dietary restriction genetic analysis melting neuropsychological prospective response tandem mass spectrometry tertiary care tetrahydrobiopterin theories

项目摘要

In 1958, Dr Robert Guthrie was approached by Dr Robert Warner seeking aid to develop a better means to measure phenylalanine in the blood of newborns. Of this interaction was born the bacterial inhibition assay and the beginning of population-based newborn screening for phenylketonuria (PKU). Early identification of affected newborns avoided irreversible brain damage using a phenylalanine-restricted diet. While the BIA has been replaced by tandem mass spectrometry as the means to measure phenylalanine, PKU remains the paradigm for a disorder effectively treated by prospective identification of asymptomatic patients. PKU results from defects in phenylalanine hydroxylase (PAH) causing an inability to convert phenylalanine to tyrosine. Treating PKU by dietary means remained largely unchanged until several groups identified a sub- set of patients treatable using 6R-tetrahydrobiopterin (BH4), the obligatory co-factor of the PAH enzyme, without the phenylalanine restricted diet. While BH4-responsive patients are skewed to mild PKU and hyperphenyla'ianemia; classic PKU patients have been characterized as BH4 responsive. Analysis of the PAH gene is becoming an important aspect to determining BH4 response. Comprehensive analysis of the PAH gene may be performed using the universally collected newborn screening dried blood card as a source of DNA. Using the dried blood card and the emerging technology of high-resolution melt profiling, comprehensive analysis of PAH may be easily completed within 1.5 days of abnormal newborn screening results. Genotypic data will be in hand when results of the physiological Phe/ BH4 loading test are complete. Combining physiological analysis and genetic analysis will lead to effective identification of BH4 responsive PKU patients. Cataloging PAH mutations resulting in BH4 responsive disease is underway thus developing a sensitive, rapidly, and cost effective means to analyze the PAH gene will have utility to clinicians and researchers. Herein is proposed the use of high resolution melt profiling to develop a simplified and streamlined means of assessing the coding sequence and intronic regions critical to mRNA processing in the PAH gene. High resolution melt profiling is rapid with sensitivity at least equal to DNA sequence analysis and in excess of other pre-sequence scanning technologies. High resolution melt profiling will play a role to identify BH4 responsive PKU patients.

1958 年，罗伯特·华纳 (Robert Warner) 博士找到罗伯特·格思里 (Robert Guthrie) 博士寻求帮助，以开发更好的方法测量新生儿血液中的苯丙氨酸。这种相互作用催生了细菌抑制测定并开始进行基于人群的新生儿苯丙酮尿症 (PKU) 筛查。及早识别受影响的新生儿通过限制苯丙氨酸饮食避免了不可逆转的脑损伤。虽然 BIA 作为测量苯丙氨酸的方法已被串联质谱法取代，PKU 仍然是通过前瞻性识别无症状患者来有效治疗疾病的范例。北京大学苯丙氨酸羟化酶 (PAH) 缺陷导致无法将苯丙氨酸转化为酪氨酸。通过饮食方式治疗 PKU 的方法基本上没有改变，直到几个小组确定了一种亚一组可使用 6R-四氢生物蝶呤 (BH4)（PAH 酶的必需辅助因子）治疗的患者，没有苯丙氨酸限制饮食。虽然 BH4 反应性患者倾向于轻度 PKU 和高苯血症;典型的 PKU 患者被描述为 BH4 反应性的。分析 PAH 基因正在成为决定 BH4 反应的一个重要方面。综合分析 PAH基因可以使用普遍收集的新生儿筛查干血卡作为来源进行 DNA。利用干燥的血卡和高分辨率熔体分析的新兴技术， PAH综合分析可在异常新生儿筛查后1.5天内轻松完成结果。当生理 Phe/BH4 负载测试结果完成后，即可获得基因型数据。结合生理分析和遗传分析将有效识别 BH4 反应性北大患者。正在对导致 BH4 反应性疾病的 PAH 突变进行编目，从而开发一种灵敏、快速且具有成本效益的 PAH 基因分析方法将对临床医生和研究人员。本文建议使用高分辨率熔体分析来开发简化且评估对 mRNA 加工至关重要的编码序列和内含子区域的简化方法多环芳烃基因。高分辨率熔解分析速度快，灵敏度至少等于 DNA 序列分析并超过其他前序扫描技术。高分辨率熔体分析将发挥作用识别 BH4 反应性 PKU 患者。