Newborn screening for PKU and BH4 responsiveness

1958年，罗伯特·华纳博士找到罗伯特·格思里博士寻求帮助，以开发一种更好的方法来 测定新生儿血液中的苯丙氨酸。这种相互作用产生了细菌抑制试验。 以及开始以人群为基础的新生儿苯丙酮尿症(PKU)筛查。及早识别 使用限制苯丙氨酸的饮食，受影响的新生儿避免了不可逆转的脑损伤。而BIA 已被串联质谱仪取代为测定苯丙氨酸的手段，北京大学仍然是 通过对无症状患者的前瞻性识别来有效治疗疾病的范例。北大 苯丙氨酸羟基酶(PAH)缺陷导致苯丙氨酸无法转化为 酪氨酸。通过饮食手段治疗PKU基本保持不变，直到几个小组发现了一个亚 一组可以使用6R-四氢生物蝶呤(BH4)治疗的患者，BH4是PAH酶的必需辅助因子， 没有苯丙氨酸限制的饮食。而对BH4有反应的患者倾向于轻度PKU和 高苯基性贫血；典型的PKU患者的特征是BH4反应。三、分析了 PAH基因正成为决定BH4反应的一个重要方面。综合分析了 PAH基因可利用普遍收集的新生儿筛查干血卡作为来源进行 关于DNA的。使用干血卡和新兴的高分辨率熔体剖面图技术， PAH的综合分析可能在异常新生儿筛查的1.5天内轻松完成 结果。当生理Phe/BH4负荷测试结果完成后，将获得基因分型数据。 结合生理分析和遗传分析将有效地鉴定BH4反应 北京大学的患者。对导致BH4反应性疾病的PAH突变的分类正在进行中，从而形成了一种 分析PAH基因的敏感、快速和经济有效的手段将对临床医生和 研究人员。在此建议使用高分辨率熔体剖面法来开发简化的和 简化的方法评估编码序列和内含子区域的关键的信使核糖核酸 PAH基因。高分辨率熔体分析快速，灵敏度至少与DNA序列分析相当 并且超过了其他预序扫描技术。高分辨率熔体剖面将发挥作用 识别对BH4有反应的PKU患者。

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 While the BIA has been replaced by tandem mass spectrometry as the means to measure phenylalanine, PKU remains the paradigm for a disorder effectively treated by prospective identification of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.