A comprehensive mutation analysis of RP2 and RPGR in a North American cohort of families with X-linked retinitis pigmentosa.

X-linked retinitis pigmentosa (XLRP) is a clinically and genetically heterogeneous degenerative disease of the retina. At least five loci have been mapped for XLRP; of these, RP2 and RP3 account for 10%-20% and 70%-90% of genetically identifiable disease, respectively. However, mutations in the respective genes, RP2 and RPGR, were detected in only 10% and 20% of families with XLRP.

Naturally occurring rhodopsin mutation in the dog causes retinal dysfunction and degeneration mimicking human dominant retinitis pigmentosa.

Rhodopsin is the G protein-coupled receptor that is activated by light and initiates the transduction cascade leading to night (rod) vision. Naturally occurring pathogenic rhodopsin (RHO) mutations have been previously identified only in humans and are a common cause of dominantly inherited blindness from retinal degeneration. We identified English Mastiff dogs with a naturally occurring dominant retinal degeneration and determined the cause to be a point mutation in the RHO gene (Thr4Arg).

Novel mutation in the TIMP3 gene causes Sorsby fundus dystrophy.

Objective: To determine the molecular basis of a retinopathy previously described as dominant macular subretinal neovascularization with peripheral retinal degeneration.

Methods: The TIMP3 gene was analyzed in family members, and 4 mutation-positive patients were studied using psychophysics and electroretinography.

Results: Cosegregating with disease in the family was a single base pair change in the TIMP3 gene, altering a conserved tyrosine to cysteine at amino acid position 172 (Y172C).

The nuclear receptor NR2E3 plays a role in human retinal photoreceptor differentiation and degeneration.

Normal human retinal development involves orderly generation of rods and cones by complex mechanisms. Cell-fate specification involves progenitor cell lineage and external signals such as soluble factors and cell-cell interactions. In most inherited human retinal degenerations, including retinitis pigmentosa, a mutant gene causes loss of visual function, death of mature rods, and eventually death of all cone subtypes.

Retinal dystrophy due to paternal isodisomy for chromosome 1 or chromosome 2, with homoallelism for mutations in RPE65 or MERTK, respectively.

Uniparental disomy (UPD) is a rare condition in which a diploid offspring carries a chromosomal pair from a single parent. We now report the first two cases of UPD resulting in retinal degeneration. We identified an apparently homozygous loss-of-function mutation of RPE65 (1p31) in one retinal dystrophy patient and an apparently homozygous loss-of-function mutation of MERTK (2q14.

Rod and cone visual cycle consequences of a null mutation in the 11-cis-retinol dehydrogenase gene in man.

Vertebrate vision starts with photoisomerization of the 11-cis-retinal chromophore to all-trans-retinal. Biosynthesis of 11-cis-retinal is required to maintain vision. A key enzyme catalyzing the oxidation of 11-cis-retinol is 11-cis-retinol dehydrogenase (11-cis-RDH), which is encoded by the RDH5 gene.