An Expanded Spectrum for Congenital Disorders of Glycosylation

先天性糖基化疾病的扩展谱

基本信息

批准号：
8490157
负责人：
Hudson H. Freeze
金额：
$ 29.25万
依托单位：
SANFORD BURNHAM PREBYS MEDICAL DISCOVERY INSTITUTE
依托单位国家：
美国
项目类别：
财政年份：
2013
资助国家：
美国
起止时间：
2013-08-01 至 2015-07-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8490157
关键词：
Affect Anabolism Basic Science Biochemical Biological Assay Biological Markers Biosensor Blood Coagulation Disorders Candidate Disease Gene Cardiomyopathies Cells Child Clinical Complement Congenital Disorders Cross Presentation Defect Deformity Developmental Delay Disorders Diagnosis Dimensions Disease Family Fluorescence Future Gene Targeting Genes Genome Genomics Hela Cells Hepatic Hereditary Disease Human Genome Intellectual functioning disability Intestines Libraries Light Link Mediating Methods Monitor Muscular Dystrophies Mutation N-Glycosylation Site Pathway interactions Patients Physicians Polysaccharides Protein Glycosylation Protein-Losing Enteropathies Proteins Research Personnel Science of genetics Seizures Sequence Analysis Serum Site Small Interfering RNA Transferrin Translational Research Validation base body system exome exome sequencing gene discovery genetic analysis genome sequencing genome-wide glycosylation glycosyltransferase medical specialties novel public health relevance screening skeletal

项目摘要

DESCRIPTION (provided by applicant): This project merges basic science with patient-relevant translational research because it identifies the causes of rare genetic diseases that impair protein N-glycosylation. Today, 39 genes are known to cause Congenital Disorders of Glycosylation (CDG), but we know that many CDG-causing genes remain undiscovered. This proposal uses a new, unbiased, forward-reaching, functional approach to identify these new genes. The Specific Aims build a bi-directional bridge between fundamental science and genetic defects in patients today. It will identify new genes to guide and inform physicians in their diagnosis of tomorrow's CDG patients in the sub-$1000-genome era. CDGs affect every organ system with a breath-taking array of variable clinical presentations that cross every medical specialty. Clinical presentations do not identify the gene, however, nearly all current CDG patients have an abnormal serum transferrin (Tf) glycosylation biomarker. There is no Tf-like cellular biomarker that can be used to assess glycosylation or complement candidate genes in suspected glycosylation-deficient patients. To fill this void, we constructed an ER-retained GFP with an N-glycosylation site (Glyc-ER-GFP) that allows fluorescence only when that site is unoccupied. This provides a highly sensitive N-glycan-biosensor for cells with impaired glycosylation: They glow. This novel cellular biomarker can identify new N-glycosylation genes by screening a well-established human genome-wide siRNA knockdown library for cells that glow. The known CDG genes serve as positive controls for the screening. Secondary glycosylation biomarkers and biochemical assays can confirm the novel gene's involvement in N-glycosylation. This approach has immediate and long-term payoffs. The functional glycosylation assay can identify genes to query today's CDG patients with unknown defects. In the future, subjects in the whole exome (genome) sequencing pipeline who show mutations in these genes will know it impacts the N-glycosylation pathway. The newly discovered genes will also expand the dimensions of our current understanding about protein glycosylation.

描述（由申请人提供）：该项目将基础科学与患者相关的转化研究相结合，因为它确定了损害蛋白质 N-糖基化的罕见遗传疾病的原因。如今，已知有 39 个基因会导致先天性糖基化障碍 (CDG)，但我们知道许多导致 CDG 的基因仍未被发现。该提案使用一种新的、公正的、具有前瞻性的功能方法来识别这些新基因。具体目标在基础科学和当今患者遗传缺陷之间架起了一座双向桥梁。它将识别出新的基因，以指导和告知医生诊断未来 1000 美元以下基因组时代的 CDG 患者。 CDG 通过跨各个医学专业的一系列令人惊叹的可变临床表现影响每个器官系统。临床表现无法识别该基因，但目前几乎所有 CDG 患者的血清转铁蛋白 (Tf) 糖基化生物标志物均异常。目前还没有类似 Tf 的细胞生物标志物可用于评估疑似糖基化缺陷患者的糖基化或补充候选基因。为了填补这一空白，我们构建了带有 N-糖基化位点 (Glyc-ER-GFP) 的 ER 保留 GFP，仅当该位点未被占据时才允许发出荧光。这为糖基化受损的细胞提供了高度灵敏的 N-聚糖生物传感器：它们会发光。这种新型细胞生物标志物可以通过筛选成熟的人类全基因组 siRNA 敲低文库来识别新的 N-糖基化基因，以寻找发光细胞。已知的 CDG 基因作为筛选的阳性对照。二级糖基化生物标志物和生化检测可以证实新基因参与 N-糖基化。这种方法具有即时和长期的回报。功能性糖基化检测可以识别基因，以查询当今具有未知缺陷的 CDG 患者。将来，整个外显子组（基因组）测序流程中显示这些基因突变的受试者将知道它会影响 N-糖基化途径。新发现的基因也将扩展我们目前对蛋白质糖基化的理解。