Dryja T P, Berson E L, Rao V R, Oprian D D
Berman-Gund Laboratory, Harvard Medical School, Boston, Massachusetts 02114.
Nat Genet. 1993 Jul;4(3):280-3. doi: 10.1038/ng0793-280.
A number of mutations in the rhodopsin gene have been shown to cause both dominant and recessive retinitis pigmentosa. Here we describe another phenotype associated with a defect in this gene. We discovered a patient with congenital stationary night blindness who carries the missense mutation Ala292Glu. When coupled with 11-cis-retinal in vitro, Ala292Glu rhodopsin is able to activate transducin in a light-dependent manner like wild-type rhodopsin. However, without a chromophore, Ala292Glu opsin anomalously activates transducin. We speculate that the rod dysfunction in this patient is due to an abnormal, continuous activation of transducin by mutant opsin molecules in photoreceptor outer segments.
视紫红质基因中的一些突变已被证明会导致显性和隐性视网膜色素变性。在此，我们描述了与该基因缺陷相关的另一种表型。我们发现了一名患有先天性静止性夜盲症的患者，其携带错义突变Ala292Glu。在体外与11-顺式视黄醛结合时，Ala292Glu视紫红质能够像野生型视紫红质一样以光依赖的方式激活转导蛋白。然而，在没有发色团的情况下，Ala292Glu视蛋白会异常激活转导蛋白。我们推测，该患者的视杆细胞功能障碍是由于光感受器外段中的突变视蛋白分子异常持续激活转导蛋白所致。
