Referenced in: none

Automatically associated channels: TRP , TRPM , TRPM1

Title: Whole-exome sequencing identifies mutations in GPR179 leading to autosomal-recessive complete congenital stationary night blindness.

Authors: Isabelle Audo, Kinga Bujakowska, Elise Orhan, Charlotte M Poloschek, Sabine Defoort-Dhellemmes, Isabelle Drumare, Susanne Kohl, Tien D Luu, Odile Lecompte, Eberhart Zrenner, Marie-Elise Lancelot, Aline Antonio, Aurore Germain, Christelle Michiels, Claire Audier, Mélanie Letexier, Jean-Paul Saraiva, Bart P Leroy, Francis L Munier, Saddek Mohand-Saïd, Birgit Lorenz, Christoph Friedburg, Markus Preising, Ulrich Kellner, Agnes B Renner, Veselina Moskova-Doumanova, Wolfgang Berger, Bernd Wissinger, Christian P Hamel, Daniel F Schorderet, Elfride De Baere, Dror Sharon, Eyal Banin, Samuel G Jacobson, Dominique Bonneau, Xavier Zanlonghi, Guylene Le Meur, Ingele Casteels, Robert Koenekoop, Vernon W Long, Francoise Meire, Katrina Prescott, Thomy de Ravel, Ian Simmons, Hoan Nguyen, Hélène Dollfus, Olivier Poch, Thierry Léveillard, Kim Nguyen-Ba-Charvet, José-Alain Sahel, Shomi S Bhattacharya, Christina Zeitz

Journal, date & volume: Am. J. Hum. Genet., 2012 Feb 10 , 90, 321-30

PubMed link: http://www.ncbi.nlm.nih.gov/pubmed/22325361

Abstract
Congenital stationary night blindness (CSNB) is a heterogeneous retinal disorder characterized by visual impairment under low light conditions. This disorder is due to a signal transmission defect from rod photoreceptors to adjacent bipolar cells in the retina. Two forms can be distinguished clinically, complete CSNB (cCSNB) or incomplete CSNB; the two forms are distinguished on the basis of the affected signaling pathway. Mutations in NYX, GRM6, and TRPM1, expressed in the outer plexiform layer (OPL) lead to disruption of the ON-bipolar cell response and have been seen in patients with cCSNB. Whole-exome sequencing in cCSNB patients lacking mutations in the known genes led to the identification of a homozygous missense mutation (c.1807C>T [p.His603Tyr]) in one consanguineous autosomal-recessive cCSNB family and a homozygous frameshift mutation in GPR179 (c.278delC [p.Pro93Glnfs(∗)57]) in a simplex male cCSNB patient. Additional screening with Sanger sequencing of 40 patients identified three other cCSNB patients harboring additional allelic mutations in GPR179. Although, immunhistological studies revealed Gpr179 in the OPL in wild-type mouse retina, Gpr179 did not colocalize with specific ON-bipolar markers. Interestingly, Gpr179 was highly concentrated in horizontal cells and Müller cell endfeet. The involvement of these cells in cCSNB and the specific function of GPR179 remain to be elucidated.