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）是男性智力迟钝的最常见原因。FRAX的发病率在男性中为1/4000，在女性中为1/8000。FRAX是由FMR 1基因5'非翻译区（UTR）的CGG三核苷酸重复序列扩增引起的。该基因位于染色体Xq27.3。在正常个体中，FMR 1基因的5' UTR含有5至45个CGG重复。然而，在FRAX患者中发现了超过200个重复。目前，Southern印迹分析用于检查FRAX基因的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和昂贵的。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反应不能扩增CGG扩增的长片段。最近，我们开发了一种新的，高效，准确的诊断FRAX的测试。该测试依赖于通过位点特异性多重置换扩增（SSMDA）扩增CGG重复扩增，其能够扩增基因组中富含GC的区域的非常长的延伸。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，使用这种新的分子基础上的筛选方法，我们可以开发一个有效的，快速的和低成本的筛选测试FRAX具有广泛的商业应用。我们预计，第一阶段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，适用于高通量使用。如果成功，我们预计这些1期研究将进入2期研究。如果广泛应用，该策略将适用于诊断FRAX携带者和FRAX个体。