MOLECULAR GENETICS OF NAIL PATELLA SYNDROME

指甲髌骨综合征的分子遗传学

• 批准号: 2732910
• 负责人: IAIN R MCINTOSH
• 金额: $ 21.21万
• 依托单位: JOHNS HOPKINS UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1997
• 资助国家: 美国
• 起止时间: 1997-07-01 至 2000-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2732910
• 关键词: alleles; artificial chromosomes; clinical research; congenital skeletal disorder; cytogenetics; denaturing gradient gel electrophoresis; developmental genetics; family genetics; fluorescent in situ hybridization; gene expression; gene rearrangement; genetic library; genetic mapping; genetic markers; human genetic material tag; northern blottings; nucleic acid probes; phenotype; point mutation; polymerase chain reaction; sequence tagged sites; single strand conformation polymorphism; southern blotting

The nail patella syndrome (NPS) represents a classic example of pleiotropy, exhibiting nail dysplasia, hypoplasia of the patella, radial head and scapula, iliac exostoses, club foot deformities and, occasionally, nephritis and ocular abnormalities. Although first recognized as an inherited disorder nearly 100 years ago, the basic defect remains unknown. Identification of the disease gene will illuminate the developmental process common to the affected tissues. In particular, a greater understanding of skeletogenesis will be gained. Previous work has placed the NPS locus near the adenylate kinase gene (AK1) on chromosome 9q34. Genetic linkage analysis using highly polymorphic dinucleotide repeats has reduced the candidate region to approximately 1cM between AK1 and the anonymous markers D9S60, D9S266 and D9S1113. Four polymorphic markers each give LOD scores greater than 10 with no recombination. Since no candidate gene can be placed in this interval with confidence a positional cloning approach is most likely to be successful in identification of the disease gene. The genetic interval will be refined using families not available for previous analyses to search for informative recombination events. The physical interval will be determined by establishment of a series of overlapping YAC clones covering the candidate region using STS fingerprinting. This contig will be assessed for candidate genes by testing ESTs previously placed in this region to determine whether they lie within the interval and exhibit a pattern of expression or other characteristics compatible with an NPS candidate gene. If necessary, novel genes will be identified within the interval by isolation of coding sequences (exon trapping) from a contig of cosmid or BAC clones covering the region. Proof of a gene's involvement in NPS will require demonstration of a de novo mutation in a sporadic case supported by identification of mutations segregating with the phenotype in multiplex families. Candidate genes will be tested for genomic rearrangements by Southern blotting, for aberrant gene expression by Northern blotting and RT-PCR, and for point mutations by a modified SSCP protocol. The range of mutations which cause NPS will be determined to facilitate recognition of functional domains within the gene product. Genotype-phenotype analyses will be performed to assess the involvement of different alleles in interfamilial phenotype variation. Identification of the NPS gene may reveal means by which serious aspects of the phenotype (nephritis, bone deformity) might be ameliorated not only in NPS patients but in persons affected with these conditions in isolation.

指甲-膝盖骨综合征(NPS)是典型的 多发性，表现为指甲发育不良，膝盖骨发育不良， 桡骨头和肩胛骨，髂骨外突，马蹄内翻足畸形， 偶有肾炎和眼部异常。虽然是第一 近100年前被认为是一种遗传性疾病，基本的 缺陷仍不得而知。鉴定致病基因Will 阐明受影响组织共同的发育过程。 特别是，对骨骼形成的更多了解将是 收获了。以前的工作已经将NPS基因的位置放在了腺苷酸盐附近 位于染色体9q34上的激酶基因(AK1)。利用遗传连锁分析 高度多态的二核苷酸重复减少了候选基因 AK1和匿名标记之间大约1 cM的区域 D9S60、D9S266和D9S1113。四个多态标记分别提供LOD 分数大于10，没有重组。因为没有候选人 基因可以有把握地放置在这个区间内 克隆方法最有可能在鉴定上取得成功 疾病基因。遗传间隔将使用以下方法进行细化 不适用于先前分析的要搜索的族 信息性重组事件。物理间隔将为 通过建立一系列重叠的YAC克隆来确定 使用STS指纹技术覆盖候选区域。这个重叠群 将通过先前的EST测试来评估候选基因 放置在此区域中，以确定它们是否位于 并表现出一种表达模式或其他特征 与NPS候选基因相容。如有必要，新基因 将在间隔内通过隔离编码来识别 粘粒或BAC克隆重叠群的序列(外显子捕获) 覆盖整个地区。基因参与NPS的证据将 需要在零星病例中证明从头开始突变 支持对分离的突变进行鉴定 多个家庭中的表型。候选基因将接受测试 用Southern blotting检测异常基因的基因组重排 Northern印迹和RT-PCR表达及点突变 通过修改的SSCP协议。引起NPS的突变范围 将被确定为促进功能域的识别 在基因产物中。将对基因-表型进行分析 以评估不同等位基因在 家系间表型变异。NPS基因的鉴定 可能揭示出表型的严重方面 (肾炎、骨骼畸形)可能不仅在NPS中得到改善 患者，但在受这些疾病影响的人中隔离。