Molecular Biological Research for Hereditary Retinal Degeneration

遗传性视网膜变性是一组病因不明的疾病。由于性质不明，我们没有有效的治疗方法。许多眼科研究者曾从形态学、生物化学或生理学的角度对这组疾病进行了研究。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，因此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病变和异常结果，而身体的其他部位在正常范围内，因此怀疑视网膜内特异性产生的蛋白质发生了遗传改变。为了获得了解遗传性视网膜变性的遗传本质的线索，检查了视网膜特异性蛋白质的cDNA克隆。第一步，获得视紫红质、Irbp、Cralbp、转导素α亚基、视网膜S抗原和33kDa蛋白的cDNA克隆，并转染E. coli JM 109。作为本项目的第二步，我们利用聚合酶链反应和限制性片段长度多态性技术，对视网膜色素变性患者的基因组DNA进行了研究，特别是对视紫红质基因进行了研究。结果发现同一个常染色体显性遗传视网膜色素变性家系的2例患者存在视紫红质基因点突变，提示视紫红质基因可能与某种视网膜色素变性的发病有关。

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.