title: Phenotype variations of retinal dystrophies caused by mutations in the RLBP1 gene.
abstract: OBJECTIVE
  Mutations in the RLBP1 gene encoding the cellular retinaldehyde-binding protein (CRALBP) cause autosomal recessive progressive retinopathy, such as retinitis punctata albescens (RPA), Bothnia-type dystrophy (BD), Newfoundland rod-cone dystrophy (NFRCD), retinitis pigmentosa (RP) and fundus albipunctatus (FA). We present the clinical heterogeneity and genetic findings of seven patients from five families with RLBP1 mutations, including three novel mutations.
  
  
  METHODS
  Seven patients underwent complete ophthalmological examination including psychophysical tests (visual acuity, colour vision, visual field, dark adaptation) and electrophysiology (Ganzfeld and multifocal ERG). Additionally, fundus photography, autofluorescence (FAF) and spectral domain optical coherence tomography (OCT) recordings were performed. Genomic DNA was analysed by high-throughput sequencing for all RP-related genes in a diagnostic set-up.
  
  
  RESULTS
  The patients presented with variable phenotypes, including RPA, BD, RP and a mild form of NFRCD. No detectable or severely depressed responses in electrophysiological examinations were seen in all cases. Visual field constriction was variable among individuals. Severely reduced visual acuity was only observed in the patient presenting with BD. The other patients retained mild to moderate reduction of visual function. Despite the morphological differences, central retinal thinning - as a common feature - could be observed.
  
  
  CONCLUSIONS
  The fact that different mutations in RLBP1 are correlated with quite different morphological and functional characteristics outlines the complexity of the protein. Identifying new mutations and comparing the different phenotypes may help to better understand the function of the protein and the consequences in pathological changes that involve RPE and choroid.
authors.affiliation: Centre for Ophthalmology, University of Tübingen, Tübingen, Germany.
authors.forename: Stephanie
authors.initials: S
authors.lastname: Hipp
authors.affiliation: Institute for Ophthalmic Research, University of Tübingen, Tübingen, Germany.
authors.forename: Gergely
authors.initials: G
authors.lastname: Zobor
authors.affiliation: CeGaT GmbH, Tübingen, Germany.
authors.forename: Nicola
authors.initials: N
authors.lastname: Glöckle
authors.affiliation: CeGaT GmbH, Tübingen, Germany.
authors.forename: Julia
authors.initials: J
authors.lastname: Mohr
authors.affiliation: Molecular Genetics Laboratory, Institute for Ophthalmic Research, University of Tübingen, Tübingen, Germany.
authors.forename: Susanne
authors.initials: S
authors.lastname: Kohl
authors.affiliation: Institute for Ophthalmic Research, University of Tübingen, Tübingen, Germany.|Werner Reichardt Center for Integrative Neuroscience, University of Tübingen, Tübingen, Germany.
authors.forename: Eberhart
authors.initials: E
authors.lastname: Zrenner
authors.affiliation: Molecular Genetics Laboratory, Institute for Ophthalmic Research, University of Tübingen, Tübingen, Germany.
authors.forename: Nicole
authors.initials: N
authors.lastname: Weisschuh
authors.affiliation: Institute for Ophthalmic Research, University of Tübingen, Tübingen, Germany.
authors.forename: Ditta
authors.initials: D
authors.lastname: Zobor
mesh_terms: D000328:Adult; D000368:Aged; D002352:Carrier Proteins / Q000235:genetics*; D002648:Child; D004596:Electroretinography; D005260:Female; D005451:Fluorescein Angiography; D056726:Genetic Association Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D009154:Mutation; D010641:Phenotype; D058499:Retinal Dystrophies / Q000175:diagnosis / Q000235:genetics*; D035781:Siblings; D041623:Tomography, Optical Coherence; D014792:Visual Acuity / Q000502:physiology; D055815:Young Adult
chemical_list: C020932:11-cis-retinal-binding protein; D002352:Carrier Proteins
keywords: RLBP1 mutations; genotype-phenotype correlations; retinitis pigmentosa; retinitis punctata albescens