Cases reported "Retinitis Pigmentosa"

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1/29. Photoreceptor rosettes in autosomal dominant retinitis pigmentosa with reduced penetrance.

    We performed histopathologic and immunofluorescence studies of autopsy eyes from a 73-year-old woman with autosomal dominant retinitis pigmentosa from a family with reduced penetrance. light microscopic examination showed extensive photoreceptor loss in most regions. In the temporal midperiphery of the retina, there were patches of remaining photoreceptors, some arranged in rosettes. Electron microscopic examination showed that these rosettes were composed mostly of rods, with a few cone-like inner segments. The malformed photoreceptor elements in the rosette lumens stained positively with anti-rhodopsin, but not with anti-red- and green-cone opsin or anti-blue-cone opsin. To our knowledge, this is the first report of photoreceptor rosettes containing rod photoreceptors in a case of retinitis pigmentosa. Future studies of additional patients will be needed to determine if the rod-abundant rosettes seen in our patient are a characteristic finding of autosomal dominant retinitis pigmentosa with reduced penetrance.
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2/29. Description of a new mutation in rhodopsin, Pro23Ala, and comparison with electroretinographic and clinical characteristics of the Pro23His mutation.

    OBJECTIVES: To report the clinical characteristics of a family with autosomal dominant retinitis pigmentosa caused by a proline-to-alanine mutation at codon 23 (Pro23Ala) of the rhodopsin gene and to compare this phenotype with that associated with the more common proline-to-histidine mutation at codon 23 (Pro23His). methods: We examined 6 patients within a single pedigree. The electroretinograms (ERGs) of 35 patients with known Pro23His mutations and of 22 healthy individuals were reviewed. Scotopic dim flash-response amplitudes, maximum combined-response amplitudes, and photopic-response amplitudes from the ERGs of these patients were plotted against age. The ERG indices of 5 individuals in the Pro23Ala family were compared with those of the patients with Pro23His mutations and of healthy individuals. Multiple linear regression was performed to evaluate the effect of age and mutation type on amplitudes. mutation detection was performed using single-strand conformation polymorphism analysis, followed by automated dna sequencing. RESULTS: patients with the Pro23Ala mutation have a clinical phenotype characterized by onset of symptoms in the second to fourth decades of life, loss of superior visual field with relatively well-preserved inferior fields, and mild nyctalopia. Comparison with patients with the Pro23His mutation demonstrates statistically significant differences (P<.001) in responses to dim flash, maximum combined, and photopic responses between patients with these mutations after controlling for the effects of age. patients with Pro23Ala mutations were less affected by ERG criteria than patients with Pro23His mutations. patients with Pro23Ala mutations also differed significantly from healthy patients in all ERG indices examined (P<.001), after controlling for age. CONCLUSION: We describe a rare mutation in codon 23 of rhodopsin causing autosomal dominant retinitis pigmentosa. The retinal dystrophy associated with the Pro23Ala mutation is characteristically mild in presentation and course, with greater preservation of ERG amplitudes than the more prevalent Pro23His mutation. Arch Ophthalmol. 2000;118:1269-1276
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3/29. Identification and in vitro expression of novel CDH23 mutations of patients with Usher syndrome type 1D.

    Usher syndrome (USH) is a group of autosomal recessive sensory disorders characterized by progressive retinitis pigmentosa (RP) and sensorineural hearing impairment. Usher syndrome type 1 (USH1), with additional vestibular dysfunction, represents the most severe form and shows extensive allelic and non-allelic heterogeneity. At least six USH1 loci exist (USH1A-F), and four of the underlying genes have been identified. Recently, a novel gene, cadherin 23 (CDH23), was shown to be mutated in USH1D. We performed mutation screening by single strand conformation polymorphism (SSCP) analysis and direct sequencing on 33 USH1 patients previously excluded for USH1B and USH1C. On eight disease alleles of four patients, four different mutations were identified, three of them novel (c.6933delT, c.5712G-->A, and IVS45-9G-->A). Exon trapping experiments were performed with two mutations. In the case of a c.5712G-->A transition of the last base of exon 42, that is an apparently synonymous mutation, skipping of exon 42 was observed. By the mutation IVS45-9G-->A, a novel splice acceptor site was created and the insertion of 7 intronic bp was observed. Two mutations, IVS45-9G-->A and the previously described IVS51 5G-->A, were each found in more than one patient. Haplotype analysis by SNPs within CDH23 suggests common ancestors for each of the mutations. Among the total of 52 USH1 cases studied by us, CDH23 mutations account for about 10% of all disease alleles. Our results further suggest that in patients with a typical USH1D phenotype, a significant portion of CDH23 mutations leads to premature termination of translation or loss of numerous amino acid residues, with a high frequency of changes causing aberrant splicing of CDH23 mRNA.
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4/29. The microsystems based visual prosthesis for optic nerve stimulation.

    The microsystems based visual prosthesis (MiViP) visual prosthesis generates visual perceptions well below safety and stimulator saturation limits. These perceptions, called phosphenes, are of reasonably small size and are broadly distributed in the visual field. They can thus be used to convey useful visual information. Psychophysical evaluations are being performed in order to assess the implantee's benefits in the use of the MiViP optic nerve visual prosthesis. In a pattern-recognition task, the performance improved regularly with practice with an increasing score and a decreasing delay to recognition. These observations open the way toward an evaluation of general mobility improvement with the portable system. In conclusion, the results obtained so far still support the potential usefulness of the optic nerve visual prosthesis. A low-resolution artificial vision can be expected from the prosthesis after extensive training.
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5/29. Bilateral macular hole formation in a patient with retinitis pigmentosa.

    A 47-year-old woman known to have retinitis pigmentosa (RP) developed macular holes in each eye. Examination and fluorescein angiography demonstrated a partial thickness macular hole in the right eye and a full thickness one in the left eye. It was concluded that macular hole formation can occur in patients with RP, but the exact cause of macular hole development in these patients is uncertain.
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6/29. A mitochondrial tRNA(His) gene mutation causing pigmentary retinopathy and neurosensorial deafness.

    We have identified a heteroplasmic G to A mutation at position 12,183 of the mitochondrial transfer rna histidine (tRNA(His)) gene in three related patients. These phenotypes varied according to mutation heteroplasmy: one had severe pigmentary retinopathy, neurosensorial deafness, testicular dysfunction, muscle hypotrophy, and ataxia; the other two had only retinal and inner ear involvement. The mutation is in a highly conserved region of the T(psi)C stem of the tRNA(His) gene and may alter secondary structure formation. This is the first described pathogenic, maternally inherited mutation of the mitochondrial tRNA(His) gene.
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7/29. Psychosis in a patient with Usher syndrome: a case report.

    The present report is the case of a 26-year-old man, born with Usher syndrome. The patient had had a significant hearing impairment since birth and had developed retinitis pigmentosa. He had originally been diagnosed with a depressive disorder and treated with antidepressants, with no subsequent improvement in his mental state. Following a deterioration in his mental state he was admitted for reassessment at the Queen Elizabeth Psychiatric Hospital, Birmingham, and antidepressants were stopped. It subsequently became apparent from observations, interviews with the patient and information from the patient's carers and relatives that he had a psychotic illness. Treatment was started with the antipsychotic drug risperidone, after which he showed significant improvement. The association between Usher syndrome and psychosis is discussed.
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8/29. Photoreceptor rosettes with blue cone opsin immunoreactivity in retinitis pigmentosa.

    Immunocytochemistry has rarely been performed on donor retinas from patients with retinitis pigmentosa (RP), due to routine storage of tissues in fixatives that reduce or destroy antigenicity. The authors have developed a method to circumvent this problem and report light and electron microscopic histopathology and immunocytochemistry of an unusual retina from a 76-year-old man with multiplex RP. The retina shows loss of photoreceptors throughout (particularly rods), shortened foveal cone outer segments, and displaced photoreceptors in rosettes and tubules, an atypical pattern for RP. Antigenicity was recovered in this retina by treatment with sodium borohydride, and 17 antigens normally found in retina are present with expected distribution, although many cells have abnormal morphology. Most cone outer segments are immunoreactive with anti-blue but not anti-red/green cone opsin, whereas blue cone sensitivity is preferentially lost in many cases of RP. Psychophysical testing of the patient's sister, who has the same retinal disease, showed reduced rod and red/green cone sensitivities. This was consistent with the diminished numbers and size of rods and red/green cones found by immunocytochemistry in her brother's retina. The sister did not show blue cone hypersensitivity characteristic of a recently described retinal degeneration known as the "enhanced S cone syndrome."
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9/29. Pigmentary retinal degeneration and Coats' disease: a case study.

    We report a 22-year-old Hispanic man with familial congenital nystagmus, iris transillumination, and pigmentary retinal anomalies with subretinal fatty exudates similar to those seen in Coats' disease. Direct treatment of the telangiectatic vessels with cryotherapy caused a subretinal hemorrhage. We therefore recommend surrounding the area of abnormal vessels (posterior to vessels and between vessels and ora serrata) with cryotherapy to reverse the formation of the vascular anomalies.
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10/29. Minor Xp21 chromosome deletion in a male associated with expression of Duchenne muscular dystrophy, chronic granulomatous disease, retinitis pigmentosa, and McLeod syndrome.

    We are reporting a male patient who suffered from chronic granulomatous disease associated with cytochrome b-245 deficiency and McLeod red cell phenotype, Duchenne muscular dystrophy, and retinitis pigmentosa. On cytogenetic analysis, he seemed to have a very subtle interstitial deletion of part of band Xp21. Since it was impossible to know whether this material was truly deleted or inserted elsewhere in the genome, somatic cell and molecular studies were carried out. In somatic cell hybrids, the deleted x chromosome was isolated on a Chinese hamster background. Southern blot analysis with 20 single-copy probes, that had been mapped to the X short arm, led to the discovery of one (probe 754) that is missing from this patient's x chromosome and also from his total dna. This proves that he, indeed, has a deletion rather than a balanced insertion. The results provide cytological mapping information for the X-linked phenotypes present in this patient. Furthermore, probe 754 recognizes a restriction fragment length polymorphism of high frequency that makes it the most powerful probe currently available for linkage studies with X-linked muscular dystrophy.
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