Properties and Therapeutic Implications of an Enigmatic D477G RPE65 Variant Associated with Autosomal Dominant Retinitis Pigmentosa

Autor: Robert K. Koenekoop, Peter Humphries, Anna-Sophia Kiang, Marian M. Humphries, G. Jane Farrar, Matthew Campbell, Ema Ozaki, Paul F. Kenna
Rok vydání: 2020
Předmět:
Male
knock-in mouse models
0301 basic medicine
Leber Congenital Amaurosis
Review
RPE65
Disease
medicine.disease_cause
Choroideremia
Mice
chemistry.chemical_compound
0302 clinical medicine
Protein Isoforms
Gene Knock-In Techniques
Age of Onset
Genetics (clinical)
Genes
Dominant

Genetics
Mutation
Clinical Trials
Phase I as Topic

incomplete penetrance
Penetrance
Pedigree
Retinaldehyde
Female
autosomal dominant retinitis pigmentosa
Retinitis Pigmentosa
Retinal Dystrophies
cis-trans-Isomerases
DNA
Complementary

lcsh:QH426-470
Genetic Vectors
9-cis retinaldehyde
Mutation
Missense

Biology
Proof of Concept Study
03 medical and health sciences
medicine
Animals
Humans
Point Mutation
Enzyme Replacement Therapy
Gene
Retinal
Genetic Therapy
medicine.disease
eye diseases
lcsh:Genetics
030104 developmental biology
Amino Acid Substitution
chemistry
030221 ophthalmology & optometry
sense organs
Zdroj: Genes
Genes, Vol 11, Iss 1420, p 1420 (2020)
ISSN: 2073-4425
DOI: 10.3390/genes11121420
Popis: RPE65 isomerase, expressed in the retinal pigmented epithelium (RPE), is an enzymatic component of the retinoid cycle, converting all-trans retinyl ester into 11-cis retinol, and it is essential for vision, because it replenishes the photon capturing 11-cis retinal. To date, almost 200 loss-of-function mutations have been identified within the RPE65 gene causing inherited retinal dystrophies, most notably Leber congenital amaurosis (LCA) and autosomal recessive retinitis pigmentosa (arRP), which are both severe and early onset disease entities. We previously reported a mutation, D477G, co-segregating with the disease in a late-onset form of autosomal dominant RP (adRP) with choroidal involvement; uniquely, it is the only RPE65 variant to be described with a dominant component. Families or individuals with this variant have been encountered in five countries, and a number of subsequent studies have been reported in which the molecular biological and physiological properties of the variant have been studied in further detail, including observations of possible novel functions in addition to reduced RPE65 enzymatic activity. With regard to the latter, a human phase 1b proof-of-concept study has recently been reported in which aspects of remaining vision were improved for up to one year in four of five patients with advanced disease receiving a single one-week oral dose of 9-cis retinaldehyde, which is the first report showing efficacy and safety of an oral therapy for a dominant form of RP. Here, we review data accrued from published studies investigating molecular mechanisms of this unique variant and include hitherto unpublished material on the clinical spectrum of disease encountered in patients with the D477G variant, which, in many cases bears striking similarities to choroideremia.
Databáze: OpenAIRE