Mapping and cloning genes for Keratoconus

圆锥角膜基因的定位和克隆

• 批准号: 6757592
• 负责人: Bassem A Bejjani
• 金额: $ 33.15万
• 依托单位: WASHINGTON STATE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-09-20 至 2008-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6757592
• 关键词: autosomal dominant trait; autosomal recessive trait; clinical research; cornea disorder; family genetics; gene expression; genetic mapping; genetic screening; human subject; in situ hybridization; keratoconus; messenger RNA; molecular cloning; northern blottings; nucleic acid sequence; pathologic process; polymerase chain reaction; autosomal dominant trait; autosomal recessive trait; clinical research; cornea disorder; family genetics; gene expression; genetic mapping; genetic screening; human subject; in situ hybridization; keratoconus; messenger RNA; molecular cloning; northern blottings; nucleic acid sequence; pathologic process; polymerase chain reaction

DESCRIPTION (provided by applicant): Keratoconus (KC) is a non-inflammatory thinning and anterior protrusion of the cornea. This bulging results in steepening and distortion of the cornea, altered refractive powers of the eye (both axial and refractive), and an associated reduction in visual acuity. The cause(s) of KC are unknown. Many hypotheses are based on the association of KC with other conditions, but no unitary theory explains any substantive fraction of the cases of KC. Although KC is an uncommon condition, it is the single most common cause for corneal transplantation in North America and thus carries substantial morbidity and expense. Recently we identified two distinct and independent populations (one from Ecuador, another from Lebanon) in which isolated KC seems to segregate in families either as an autosomal dominant trait with less than uniform penetrance (in Ecuador) or as an autosomal recessive trait (in Lebanon). Our goals for this proposal are to map and to clone the putative KC gene(s) in these populations as a first step toward improved understanding of the molecular pathophysiology of the disorder. To achieve these goals, we will: (1) Identify KC families in each population with more than one affected individual, evaluate clinically both patients and extended family members, analyze the pedigrees, obtain blood samples, isolate genomic DNA, and establish lymphoblastoid cell lines; (2) Determine the genetic map position of the gene(s) responsible for KC in the Ecuadorian and Lebanese families by conventional linkage analysis (affected sib-pair or related genome-wide analyses); (3) Exclude positional candidate genes by a combined positional/functional approach; (4) Identify the gene(s) responsible for KC by positional cloning and study the complete DNA sequence; (5) Test and compare any one isolated gene as a candidate for KC in the other population; and (6) Study the expression pattern of the candidate gene in mouse cornea and embryonic, juvenile, and adult ocular tissues by in situ hybridization to establish an expression profile for each gene. The identification of one or more KC gene has important implications to the under-standing of the patho-physiology of the disease and may open new avenues for therapeutic interventions.

描述（由申请人提供）：角膜结（KC）是角膜的非炎性稀疏和前突出。这种凸起会导致角膜的陡峭和变形，眼睛的折射力改变（轴向和折射率），以及视力降低。 KC的原因是未知的。许多假设基于KC与其他条件的关联，但没有统一理论解释了KC病例的任何实质性部分。尽管KC是一种罕见的条件，但它是北美角膜移植的最常见原因，因此具有大量的发病率和费用。最近，我们确定了两个独立和独立的人群（一个来自厄瓜多尔，另一个来自黎巴嫩），其中孤立的KC似乎是在家庭中划分为一种常染色体显性特征，其渗透率小于均匀的渗透率（在厄瓜多尔）或常染色体隐性特征（在黎巴嫩）。我们的这一建议的目标是在这些人群中绘制并克隆推定的KC基因，这是改善对疾病分子病理生理学的了解的第一步。为了实现这些目标，我们将：（1）确定每个人群中有一个以上受影响的个体的KC家族，评估临床患者和大家庭成员，分析血统，获得血液样本，分离基因组DNA并建立淋巴母细胞细胞系； （2）通过常规的连锁分析（受影响的SIB-PAIR或相关的全基因组分析）确定负责厄瓜多尔和黎巴嫩家族中KC的基因的遗传图位置； （3）通过合并的位置/功能方法排除位置候选基因； （4）通过位置克隆确定负责KC的基因并研究完整的DNA序列； （5）测试和比较任何一个孤立的基因作为其他人群KC的候选者； （6）通过原位杂交研究小鼠角膜和胚胎，青少年和成年眼组织中候选基因的表达模式，以建立每个基因的表达谱。一个或多个KC基因的鉴定对疾病的病理生物学的遗憾具有重要意义，并可能为治疗干预措施打开新的途径。