Development of Novel Diagnostics for Fragile X Syndrome

脆性 X 综合征新型诊断方法的开发

• 批准号: 7479456
• 负责人: SEIYU HOSONO
• 金额: $ 11.77万
• 依托单位: JS GENETICS, INC.
• 依托单位国家: 美国
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-04-20 至 2009-10-19
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7479456
• 关键词: 5' Untranslated Regions; Algorithms; Binding; Biological Assay; CGG repeat; CGG repeat expansion; Characteristics; Chromosomes; Clinical; Codon Nucleotides; Condition; Development; Diagnosis; FMR1; FMR1 Gene; Facies; Female; Forehead; Fragile X Mental Retardation Protein; Fragile X Syndrome; GC Rich Sequence; Genes; Genome; Incidence; Individual; Infertility; Jaw; Lead; Mental Retardation; Methods; Methylation; Molecular; Molecular Diagnosis; Mutation; Neurons; Numbers; Patients; Phase; Phase I Clinical Trials; Phase II Clinical Trials; Polymerase Chain Reaction; Promoter Regions; Proteins; Reaction; Screening procedure; Site; Southern Blotting; Stretching; Syndrome; Testing; Time; Translating; Translations; Trinucleotide Repeats; Untranslated Regions; X Chromosome; base; commercial application; cost; male; novel; novel diagnostics; relating to nervous system; size

DESCRIPTION (provided by applicant): Fragile X Syndrome (FRAX), is the most common cause of mental retardation in males. The incidence of FRAX is 1 per 4000 in males and 1 per 8000 in females. FRAX is caused by the expansion of a CGG trinucleotide repeat of the 5' untranslated region (UTR) of FMR1 gene. This gene is located at chromosome Xq27.3. In normal individuals, the 5' UTR of the FMR1 gene contains 5 to 45 CGG repeats. However, over 200 repeats are found in individuals with FRAX. Presently, Southern Blot analysis is used to examine the size of the repeat segment and methylation status of the FRAX gene. Yet, this test only detects the gross size of CGG repeats and is highly labor intensive and expensive. PCR analysis can be used to examine the size of CGG repeats. This approach is limited, as the PCR reaction fails to amplify long stretches of CGG expansions. Recently, we developed a novel, highly efficient, accurate, test for diagnosing FRAX. This test relies on amplifying CGG repeat expansions by Site Specific Multiple Displacement Amplification (SSMDA), which capably amplifies very long stretches of GC-rich regions in the genome. SSMDA is followed by quantitative assessment of the numbers of CGG triplet repeats using real-time Polymerase Chain Reaction. We hypothesize that using this new molecular-based screening method, we can develop an effective, rapid and low-cost screening test for FRAX with broad commercial application. We anticipate that this Phase 1 application will lead to the development of a new screening procedure for FRAX that is sensitive, accurate, inexpensive, and adaptable for high-throughput use. If successful, we anticipate these Phase 1 studies will lead to Phase 2 studies. If broadly applied, this strategy will be applicable for diagnosing carriers of FRAX and individuals with FRAX.

描述（由申请人提供）：脆性 X 综合征（FRAX）是男性智力低下的最常见原因。男性 FRAX 的发病率为每 4000 人 1 例，女性每 8000 人 1 例。 FRAX 是由 FMR1 基因 5' 非翻译区 (UTR) 的 CGG 三核苷酸重复扩增引起的。该基因位于染色体 Xq27.3。在正常个体中，FMR1基因的5'UTR包含5至45个CGG重复。然而，在患有 FRAX 的个体中发现了超过 200 个重复。目前，Southern Blot 分析用于检查 FRAX 基因重复片段的大小和甲基化状态。然而，该测试仅检测 CGG 重复序列的总大小，并且是高度劳动密集型且昂贵的。 PCR 分析可用于检查 CGG 重复序列的大小。这种方法是有限的，因为 PCR 反应无法放大 CGG 扩展的长段。最近，我们开发了一种新颖、高效、准确的 FRAX 诊断测试。该测试依赖于通过位点特异性多重置换扩增 (SSMDA) 来放大 CGG 重复序列，该技术能够放大基因组中非常长的富含 GC 的区域。 SSMDA 之后使用实时聚合酶链反应定量评估 CGG 三联体重复的数量。我们假设，使用这种新的基于分子的筛选方法，我们可以开发一种有效、快速且低成本的 FRAX 筛选测试，并具有广泛的商业应用。我们预计这一阶段 1 的应用将导致开发一种新的 FRAX 筛选程序，该程序灵敏、准确、廉价且适合高通量使用。如果成功，我们预计这些第一阶段研究将导致第二阶段研究。如果广泛应用，该策略将适用于诊断 FRAX 携带者和 FRAX 个体。