An increasing number of genes required for mitochondrial biogenesis, dynamics, or function have been found to be mutated in metabolic disorders and neurological diseases such as Leigh Syndrome. In a forward genetic screen to identify genes required for neuronal function and survival in Drosophila photoreceptor neurons, we have identified mutations in the mitochondrial methionyl-tRNA synthetase, Aats-met, the homologue of human MARS2. The fly mutants exhibit age-dependent degeneration of photoreceptors, shortened lifespan, and reduced cell proliferation in epithelial tissues.
PURPOSE: To describe the phenotypic variability in a Polish Norrie disease (ND) family associated with the missense mutation A63D. METHODS: A patient with spared vision from a Polish ND family underwent detailed ophthalmological examinations including slit-lamp biomicroscopy, ultrasound (USG), angiography, Goldmann kinetic visual field, and electroretinography (ERG). Mutation screening was carried out using the single-strand conformation polymorphism (SSCP) technique and subsequent DNA sequencing of the coding part of the ND gene.
PURPOSE: Bear bile has been used in Asia for over 3,000 years to treat visual disorders, yet its therapeutic potential remains unexplored in Western vision research. The purpose of this study was to test whether treatment of mice undergoing retinal degeneration with tauroursodeoxycholic acid (TUDCA), a primary constituent of bear bile, alters the course of degeneration. METHODS: Two retinal degeneration models were tested: the rd10 mouse, which has a point mutation in the gene encoding the beta subunit of rod phosphodiesterase, and light induced retinal damage (LIRD).
PURPOSE: Retinitis pigmentosa (RP) is a progressive neurodegenerative disease resulting in blindness for which there is no current treatment. Although the members of the family of RP diseases differ in etiology, their outcomes are the same: apoptosis of rods and then by cones. Recently, the bile acid tauroursodeoxycholic acid (TUDCA) has been shown to have antiapoptotic properties in neurodegenerative diseases, including those of the retina.
PURPOSE: Mutations in ANT, a mitochondrial ATP transporter, are typically associated with myopathy. Because of the high metabolic demands of the retina, the authors examined whether elimination of the Ant1 isoform in a transgenic mouse affects retinal function or morphology. METHODS: RT-PCR was used to confirm Ant1 expression in retinas of wild-type (WT) or Ant1(-/-) mice. Full-field ERGs were used to test retinal function under dark- and light-adapted conditions and the recovery of the photoresponse to a bright flash.
A pair of 19-year-old female identical twins was referred to our hospital with progressive visual loss. They exhibited bilateral chorioretinal atrophy involving the midperiphery on fundoscopy and fluorescein angiography. Bilateral visual field constriction was noted on dynamic Goldmann perimetry, and a markedly impaired response was observed on both photopic and scotopic electroretinograms. Cystoid macular edema was identified in both eyes on optical coherence tomography. Plasma levels of ornithine were elevated.