Molecular Biological Research for Hereditary Retinal Degeneration

遗传性视网膜变性是一类疾病，其病因尚不清楚。由于其未知的性质，我们还没有有效的治疗方法。许多眼科研究者曾用形态学、生化或生理学的方法对这类疾病进行过研究。然而，由于这些疾病的基本异常存在于我们尚未完全了解的基因中，我们还不知道这些疾病的发病机制。由于大多数患有这些疾病的患者仅在视网膜脉络膜区域表现出症状和异常发现，而身体的其他部分在正常范围内，因此怀疑视网膜内特异性产生的蛋白质被遗传改变了。为了获得了解遗传性视网膜变性的遗传性质的线索，研究了视网膜特异性蛋白的cDNA克隆。首先获得视紫红质、Irbp、Cralbp、转导蛋白（α亚基）、视网膜s抗原和33kDa蛋白的cDNA克隆，并转染大肠杆菌JM109。同时，对一些未知的视网膜特异性蛋白进行了cDNA克隆分离实验。作为该项目的第二步，我们使用聚合酶链反应和限制性片段长度多态性技术对色素性视网膜炎患者的基因组DNA进行了特别感兴趣的视紫红质基因检测。结果发现2例常染色体显性视网膜色素变性同家系患者的视紫红质基因存在点突变，提示视紫红质基因可能与某一类视网膜色素变性的发病机制有关。

Hereditary retinal degeneration is a group of disorders, whose causes have been obscure. Because of the unknown nature, we have not had effective modalities of treatment. Many ophthalmic researchers have ever studied this group of disorders by means of morphologic, biochemical or physiological methods. However, because the essential abnormalities of these disorders are in genes which we have not fully understood yet, we have not known the pathogenesis of these diseases. Since most patients with these diseases show symptomes and abnormal findings only in the retinochoroidal region while other parts of the body are within normal range, proteins specifically produced within the retina are suspected to be genetically altered.In order to obtain clues to understand genetic nature of the hereditary retinal degeneration, cDNA clones for retina specific proteins were examined. As the first step, cDNA clones for rhodopsin, Irbp, Cralbp, transducin (alpha-subunit), retinal S-antigen and 33kDa protein were obtained and transfeccted into E. coli JM109. Also, experiments were prepared for isolation of novel cDNA clones for some of unknown retina specific proteins.As the second step of this project, genomic DNA's from patients with retinitis pigmentosa were examined with a particular interest on the rhodopsin gene using polymerase chain reaction and restriction fragment length polymorphism. As a result, two cases of the same pedigree with autosomal dominant retinitis pigmentosa was found to have a point mutation in the rhodopsin gene, suggesting that rhodopsin gene could be related to the pathogenesis of a certain kind of retinitis pigmentosa.