Diagnosis in a patient with fundus albipunctatus and atypical fundus changes

Abstract

We report a case of an 11-year old Caucasian female with nyctalopia since early childhood with an atypical clinical presentation of fundus albipunctatus (FA), and a novel mutation in the RDH5 gene. In addition to white spots in the fundus, patchy areas of hypopigmentation were noted, which were reminiscent for an early stage of retinitis punctata albescens (RPA). Electroretinographic testing (ERG) showed a non-detectable, dark adapted, isolated rod response and a markedly decreased combined rod and cone response to an achromatic stimulus. After patching one eye overnight, both the isolated rod response and combined rod and cone scotopic white flash response were normal. A Goldmann-Weekers dark adapted final threshold response was also within the normal range. The patient showed a previously reported heterozygous mutation for Gly238Trp, and a novel Arg157Gln mutation. Genetic testing and extended ERG and psychophysical testing may be necessary to diagnose FA from early stages of progressive RPA.

Congenital stationary night blindness: An analysis and update of genotype–phenotype correlations and pathogenic mechanisms

“…They and recurrent mutations, including cases with homozygous mutations, represent 75.1% and 85.7% respectively of the mutations identified. Of those the c.160C>T p.Arg54* in RDH5 has been identified in Jewish families of different ethnicity (Pras et al, 2012) and three other mutations in the same gene c.712G>T p.Gly238Trp (Gonzalez-Fernandez et al, 1999;Hajali et al, 2009;Iannaccone et al, 2007;Schatz et al, 2010;Sergouniotis et al, 2011c;Yamamoto et al, 1999), c.839G>A p.Arg280His (Gonzalez-Fernandez et al, 1999;Kuroiwa et al, 2000;Miyazaki et al, 2001;Nakamura et al, 2000Nakamura et al, , 2004aNiwa et al, 2005;Sato et al, 2004) and c.928delinsGAAG p.Leu310delins-GluVal (Hayashi et al, 2006;Hirose et al, 2000;Makiyama et al, 2014;Nakamura et al, 2000;Niwa et al, 2005;Sato et al, 2004;Sekiya et al, 2003;Wada et al, 2000;Wang et al, 2008) represent founder mutations in Japanese cases of FA. Some recurrent mutations were also noted in patients with mutations in autosomal recessive and x-linked CSNB associated with the Schubert-Bornschein-type electroretinogram.…”

Mutations in RLBP1 associated with fundus albipunctatus in consanguineous Pakistani families

“…Fundus albipunctatus (FA) is a rare form of apparently stationary night blindness that is also characterised by the presence of symmetrical round white dots in the fundus with a greater concentration in the midperiphery but with normal retinal arterioles, disc and visual fields 1. In FA patients, electroretinogram (ERG) recordings yield poor responses after retinal bleaching and profoundly delayed dark adaptation improves upon prolonged exposure to darkness 1.…”

“…In FA patients, electroretinogram (ERG) recordings yield poor responses after retinal bleaching and profoundly delayed dark adaptation improves upon prolonged exposure to darkness 1. A clinically distinct disorder, retinitis punctata albescens (RPA) is characterised by nyctalopia, reduced visual acuity, multiple round white deposits in the retina, progressive attenuation of retinal arterioles, and non-detectable or severely reduced ERG recordings 2…”

VII-2 : ELECTROPHYSIOLOGIE PEDIATRIQUE : EXEMPLES Première partie

“…Les amplitudes des ERG scotopique et mixte (rod-et mixed-responses) peuvent être diminuées, voire d'aspect électronégatif pour la mixed-response (Nakamura, Skalet & Miyake, 2003). Après une adaptation de longue durée à l'obscurité, de trois heures (Nakamura et al, 2003), (Hayashi, Goto-Omoto, Takeuchi, Gekka, Ueoka & Kitahara, 2006) ou parfois davantage durant toute une nuit (Hajali, Fishman, Dryja, Sweeney & Lindeman, 2009), on observe une augmentation voire une normalisation des amplitudes.…”

“…Cependant, c'est l'analyse moléculaire qui permet d'établir avec certitude le diagnostic différentiel en mettant en évidence différentes mutations dans le gène RDH5 pour le fundus albipunctatus, (Hajali et al, 2009) et dans le gène RLBP1 pour la rétinopathie ponctuée albescente (Burstedt et al, 2008). …”