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| 2. |
- Andréasson, Sten, et al.
(författare)
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Phenotypes in three Swedish families with X-linked retinitis pigmentosa caused by different mutations in the RPGR gene
- 1997
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Ingår i: American Journal of Ophthalmology. - 1879-1891. ; 124:1, s. 95-102
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Tidskriftsartikel (refereegranskat)abstract
- PURPOSE: To assess the clinical phenotypes in three Swedish families with X-linked retinitis pigmentosa caused by different mutations in the RPGR gene. METHODS: Three families from different parts of Sweden, including nine patients with retinitis pigmentosa and six female carriers of X-linked retinitis pigmentosa, were examined clinically. Ophthalmologic examination included kinetic perimetry with a Goldmann perimeter using standardized objects I4e and V4e, dark adaptation final thresholds with a Goldmann-Weeker adaptometer, and full-field electroretinograms. RESULTS: The clinical findings in the patients demonstrated a severe form of retinitis pigmentosa with visual handicap early in life. Patients with a microdeletion of exons 8 through 10 of the RPGR gene had a more severe phenotype compared to the patients with single base-pair mutations in the introns 10 and 13 of the RPGR gene, resulting in splicing defects. Furthermore, heterozygous carriers in these families displayed a wide spectrum of clinical features, from minor symptoms to severe visual disability. CONCLUSION: These three families show a variable clinical phenotype resulting from different mutations in the RPGR gene. A microdeletion spanning at least parts of exons 8 through 10 seems to result in a severe phenotype compared to the splice defects. Heterozygous carriers of X-linked retinitis pigmentosa with these specific RPGR genotypes also show a variability of the phenotype; carriers with the microdeletion may be severely visually handicapped.
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| 3. |
- Eksandh, Louise, et al.
(författare)
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Different clinical expressions in two families with Stargardt's macular dystrophy (STGD1)
- 2001
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Ingår i: Acta Ophthalmologica Scandinavica. - : Wiley. - 1395-3907. ; 79:5, s. 524-530
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: To describe the clinical expressions, with emphasis on electrophysiological examinations, in two Swedish families with Stargardt's macular dystrophy (STGD1). Methods. Two pairs of siblings with STGD1, for whom diagnosis had been confirmed by genetic linkage to the ABCA4 gene region, were examined regarding visual acuity, kinetic perimetry, fundus photography, full-field ERG and multifocal ERG (MERG). Possible disease-causing mutations were screened for by DNA sequencing of selected regions of the ABCA4 gene. Results. All STGD1 patients, had visual acuity 0.07-0.1. The two families presented different fundus appearances, MERGs and implicit times on. 30 Hz flicker white light full-field ERGs. Genetic analysis revealed one unique sequence variation in exon 19 of the ABCA4 gene, in one allele from the patients of one of the families. This point mutation causes the amino acid substitution T972N in the ABCR protein. Conclusion. Two pairs of siblings with STGD1 presented two different expressions of the disease regarding the distribution of the retinal dysfunction. One possible molecular explanation to the different clinical expressions may be the T972N substitution present in the ABCR protein in one of the STGD1 families investigated.
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| 4. |
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| 5. |
- Ekström, Ulf, et al.
(författare)
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A Swedish family with a mutation in the peripherin/RDS gene (Arg-172-Trp) associated with a progressive retinal degeneration
- 1998
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Ingår i: Ophthalmic Genetics. - : Swets & Zeitlinger Publishers. - 1744-5094 .- 1381-6810. ; 19:3, s. 149-156
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Tidskriftsartikel (refereegranskat)abstract
- PURPOSE: To clinically characterize a Swedish family with autosomal dominant retinitis pigmentosa due to a mutation, Arg-172-Trp, in the peripherin/RDS gene. METHODS: Full clinical evaluation including kinetic visual field testing, measurement of dark-adaptation threshold, and full-field electroretinography in seven patients with autosomal dominant retinitis pigmentosa and three healthy family members. Denaturing gradient gel electrophoresis (DGGE) was used for mutation screening in seven patients and six healthy members of the family. RESULTS: Three of four siblings from the middle generation and four of the younger generation were heterozygous for the peripherin /RDS Arg-172-Trp mutation. The mutation segregated with the disease. Visual acuity decreased progressively with age and visual fields were moderately constricted in young patients, while central scotoma and constriction of the fields were detected in the family members above 50 years of age. The results from full-field electrography were comparable with a widespread retinal degeneration. CONCLUSIONS: Earlier, the peripherin/RDS Arg-172-Trp mutation was associated primarily with a macular degeneration phenotype. One previous study indicated that this mutation also can give rise to a degeneration of the more peripheral parts of the retina. In the present study, a widespread retinal degeneration is seen in the patients above 50 years of age, carrying the Arg-172-Trp mutation.
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| 6. |
- Ekström, Ulf, et al.
(författare)
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Detection of alterations in all three exons of the peripherin/RDS gene in Swedish patients with retinitis pigmentosa using an efficient DGGE system
- 1998
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Ingår i: Molecular Pathology. - 1366-8714. ; 51:5, s. 287-291
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Tidskriftsartikel (refereegranskat)abstract
- AIMS: To develop a sensitive mutation screening procedure suitable for routine analysis of the peripherin/RDS gene, and to estimate the nature and prevalence of peripherin/RDS gene mutations in Swedish patients with autosomal dominant retinitis pigmentosa. METHODS: To make the method as sensitive as possible, as many as eight segments, covering the three exons and the flanking intron sequences of the peripherin/RDS gene, were analysed by denaturing gradient gel electrophoresis. A group of 38 Swedish patients with a clinical diagnosis of autosomal dominant retinitis pigmentosa were screened for mutations in the peripherin/RDS gene. RESULTS: Three point mutations were found in four of the patients and five polymorphisms were defined. One mutation in exon 1, R172W, has been described previously in other ethnic groups as causing a macular degeneration. Another mutation, in exon 2 and causing the substitution F211L, was found in two unrelated patients. A third mutation, resulting in the likely non-pathogenic substitution S289L, as well as a polymorphism not reported previously, was found in exon 3. CONCLUSIONS: The screening procedure described allows detection of mutations in all of the exons, including the polymorphic 5' and 3' ends of the gene, and is therefore suitable for routine screening of peripherin/RDS gene defects in patients with autosomal dominant retinitis pigmentosa. The frequency of mutations found in the Swedish patient group indicates that defects in the peripherin/RDS gene might be a more common cause of autosomal dominant retinitis pigmentosa than was thought previously.
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| 7. |
- Ekström, Ulf, et al.
(författare)
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Phenotypic expression of autosomal dominant retinitis pigmentosa in a Swedish family expressing a Phe-211-Leu variant of peripherin/RDS
- 1998
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Ingår i: Ophthalmic Genetics. - : Swets & Zeitlinger Publishers. - 1744-5094 .- 1381-6810. ; 19:1, s. 27-37
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Tidskriftsartikel (refereegranskat)abstract
- PURPOSE: To characterize the clinical phenotype, with emphasis on electrophysiology, of members of a Swedish family with autosomal dominant retinitis pigmentosa due to a novel mutation, F211L, in the peripherin/RDS gene. METHODS: Nine patients with autosomal dominant retinitis pigmentosa and two healthy family members underwent a full clinical evaluation including kinetic visual field testing, measurement of dark adaptation threshold, and full-field electroretinography. Blood samples were collected and DNA analysis was performed using denaturing gradient gel electrophoresis (DGGE). RESULTS: The grandfather, six of seven siblings from the middle generation, and two young boys carried the mutation F211L in the peripherin/RDS gene. The mutation segregated with the clinical presentation of disease. Fundus examination revealed mainly macular atrophy. All assessed parameters of retinal function (visual acuity, dark adaptation threshold, visual fields, and full-field electroretinograms) demonstrated a successive reduction with increasing age. Full-field electroretinograms showed a diminished rod response in all affected individuals and a reduction of the cone b-wave amplitudes with increasing age, indicating retinitis pigmentosa. In the affected family members, the disease seems to progress at a similar rate with increasing age. CONCLUSIONS: The peripherin/RDS gene mutation F211L is associated with a clinical phenotype and includes early loss of rod function and successive reduction of cone function with increasing age, but impressively well-preserved visual acuity and visual fields in young and middle-aged patients and moderately reduced vision in the old patient. Compared to previously described phenotypes segregating with mutations in the peripherin/RDS gene, the present family demonstrates a more benign clinical phenotype, which is concordant within the family.
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| 8. |
- Friedman, James S., et al.
(författare)
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Mutations in a BTB-Kelch Protein, KLHL7, Cause Autosomal-Dominant Retinitis Pigmentosa
- 2009
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Ingår i: American Journal of Human Genetics. - : Elsevier BV. - 0002-9297. ; 84:6, s. 792-800
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Tidskriftsartikel (refereegranskat)abstract
- Retinitis pigmentosa (RP) refers to a genetically heterogeneous group of progressive neurodegenerative diseases that result in dysfunction and/or death of rod and cone photoreceptors in the retina. So far, 18 genes have been identified for autosomal-dominant (ad) RP. Here, we describe an adRP locus (RP42) at chromosome 7p15 through linkage analysis in a six-generation Scandinavian family and identify a disease-causing mutation, c.449G -> A (p.S150N), in exon 6 of the KLHL7 gene. Mutation screening of KLHL7 in 502 retinopathy probands has revealed three different missense mutations in six independent families. KLHL7 is widely expressed, including expression in rod photoreceptors, and encodes a 75 kDa protein of the BTB-Kelch Subfamily within the BTB superfamily. BTB-Kelch proteins have been implicated in ubiquitination through Cullin E3 ligases. Notably, all three putative disease-causing KLHL7 mutations are within a conserved BACK domain; homology modeling suggests that mutant amino acid side chains can potentially fill the cleft between two helices, thereby affecting the ubiquitination complexes. Mutations in an identical region of another BTB-Kelch protein, gigaxonin, have previously been associated with giant axonal neuropathy. Our studies suggest an additional role of the ubiquitin-proteasome protein-degradation pathway in maintaining neuronal health and in disease.
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| 9. |
- Fujita, Ricardo, et al.
(författare)
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Analysis of the RPGR gene in 11 pedigrees with the retinitis pigmentosa type 3 genotype: Paucity of mutations in the coding region, but splice defects in two families
- 1997
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Ingår i: American Journal of Human Genetics. - : Elsevier BV. - 0002-9297. ; 61:3, s. 571-580
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Tidskriftsartikel (refereegranskat)abstract
- X-linked retinitis pigmentosa (XLRP) is a severe form of inherited progressive retinal degeneration. The RP3 (retinitis pigmentosa type 3) locus at Xp21.1 is believed to account for the disease in the majority of XLRP families. Linkage analysis and identification of patients with chromosomal deletion have refined the location of the RP3 locus and recently have led to the cloning of the RPGR (retinitis pigmentosa GTPase regulator) gene, which has been shown to be mutated in 10%15% of XLRP patients. In order to systematically characterize the RPGR mutations, we identified 11 retinitis pig-mentosa type III (RP3) families by haplotype analysis. Sequence analysis of the PCR-amplified genomic DNA from patients representing these RP3 families did not reveal any causative mutation in RPGR exons 219, spanning > 98% of the coding region. In patients from two families, we identified transition mutations in the intron region near splice sites (IVS10/3 and IVS13-8). RNA analysis showed that both splice-site mutations resulted in the generation of aberrant RPGR transcripts. Our results support the hypothesis that mutations in the reported RPGR gene are not a common defect in the RP3 subtype of XLRP and that a majority of causative mutations may reside either in as yet unidentified RPGR exons or in another nearby gene at Xp21.1.
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| 10. |
- Gränse, Lotta, et al.
(författare)
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Electrophysiologic findings in two young patients with Bothnia dystrophy and a mutation in the RLBP1 gene
- 2001
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Ingår i: Ophthalmic Genetics. - : Swets & Zeitlinger Publishers. - 1744-5094 .- 1381-6810. ; 22:2, s. 97-105
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: To characterize the clinical phenotype, with emphasis on electrophysiology, of two children with suspected Bothnia dystrophy. Methods: Two unrelated affected patients, 10 and 11 years old, were studied. Ophthalmological examination included testing of visual acuity, fundus inspection and fundus photography, kinetic perimetry, full-field electroretinogram (ERG), and multifocal ERG. The presence of a mutation in exon 7 of the RLBP1 gene was investigated by DNA sequencing. Results: Both patients were homozygous for the Arg234Trp-causing mutation in the RLBP1 gene, but the resulting disease phenotype appeared to vary somewhat between them. Visual acuity was moderately reduced in one patient and normal in the other. Fundus inspection at this age revealed no pathology in either patient and there were no signs of retinitis punctata albescens, which has been described previously as a frequent clinical feature of Bothnia dystrophy. The result of kinetic perimetry was normal. The final rod threshold was moderately elevated. Full-field ERG demonstrated the uncommon combination of absent rod response and normal cone response after 40 minutes of dark adaptation. However, after prolonged dark adaptation (20-24 h), both the rod response and the dark adaptation threshold became normal. Multifocal ERG was performed in one of the patients (the one with normal visual acuity and normal fundus appearance) and showed a reduced cone response in the central region of the tested area. There was no improvement of the multifocal ERG result after 20-24 h of dark adaptation. Conclusion: Patients with mutations in the RLBP1 gene (Arg234Trp) may have a normal fundus appearance early in the disease course. Multifocal ERG can be used for the objective documentation of the disturbed macular function, especially when the patient's visual acuity and fundus appearance are normal. The rod response is absent in the electroretinogram; however, after prolonged dark adaptation (20-24 hours), the rods recover completely. The central cones do not seem to recover.
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