An Expanded Spectrum for Congenital Disorders of Glycosylation

先天性糖基化疾病的扩展谱

• 批准号: 8706197
• 负责人: Hudson H. Freeze
• 金额: $ 23.69万
• 依托单位: SANFORD BURNHAM PREBYS MEDICAL DISCOVERY INSTITUTE
• 依托单位国家: 美国
• 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/8706197
• 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

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与患者相关的转化研究融合在一起，因为它确定了罕见的遗传疾病的原因，这些疾病会损害蛋白质N-糖基化。如今，已知39个基因会引起先天性糖基化（CDG），但我们知道许多引起CDG的基因仍然未被发现。该建议使用一种新的，公正的，前瞻性的，功能性的方法来识别这些新基因。当今患者的基本科学与遗传缺陷之间建立了双向桥梁。它将确定新的基因，以指导并告知医生，以诊断出低于$ 1000基因的时代明天的CDG患者。 CDG通过横穿每个医学专业的可变临床表现来影响每个器官系统。临床表现未鉴定基因，但是，几乎所有当前的CDG患者均具有异常的血清转移蛋白（TF）糖基化生物标志物。没有TF样细胞生物标记物可用于评估可疑糖基化缺陷患者中的糖基化或补体候选基因。为了填补这一空白，我们用N-糖基化位点（GLYC-ER-GFP）构建了ER保留的GFP，该GFP只有在该位点未占用时才允许荧光。这为糖基化受损的细胞提供了高度敏感的N-聚糖生物传感器：它们发光。这种新型的细胞生物标志物可以通过筛选出良好的人类基因组siRNA敲低文库来鉴定新的N-糖基化基因。已知的CDG基因是筛查的阳性对照。次生糖基化生物标志物和生化测定可以证实新基因参与N-糖基化。这种方法具有立即和长期的回报。功能性糖基化测定可以鉴定基因以查询当今缺陷的CDG患者。将来，在这些基因中显示突变的整个外显子组（基因组）测序管道中的受试者将知道它会影响N-糖基化途径。新发现的基因还将扩大我们当前对蛋白质糖基化的理解的维度。