AIM: To describe long term follow-up in a family with GUCY2D dominant cone dystrophy. METHODS: Optical coherence tomography scans and fundus autofluorescence images were obtained. Flash and pattern electroretinograms(...AIM: To describe long term follow-up in a family with GUCY2D dominant cone dystrophy. METHODS: Optical coherence tomography scans and fundus autofluorescence images were obtained. Flash and pattern electroretinograms(ERGs) and occipital pattern reversal visual evoked potentials were recorded. RESULTS: Two members of the same family(father and son) were identified to have the heterozygous R838 C mutation in the GUCY2D gene. The father presented at the age of 45 with bilateral bull’s eye maculopathy and temporal disc pallor. Over 13 y of serial follow up visits, the bull’s eye maculopathy progressed gradually into macular atrophy. Electrophysiological tests were significantly degraded suggesting poor macular function. Spectraldomain optical coherence tomography(SD-OCT) scans showed progressive loss and disruption of the ellipsoid layer at the foveal level. His son presented at the age of 16 with bilateral granular retinal pigment epithelial changes in both maculae. Electrophysiological testing was initially borderline normal but has gradually deteriorated to show reduced cone ERGs and macula function. SD-OCT demonstrated gradual macular thinning and atrophy bilaterally. Unlike his father, there was no disruption of the ellipsoid layer.CONCLUSION: Both family members exhibited gradual changes in their fundi, electrophysiological testing and multimodal imaging. Changes were milder than those observed in other mutations of the same gene.展开更多
AIMTo identify the disease-causing gene mutation in a Chinese pedigree with autosomal dominant cone-rod dystrophy (adCORD).METHODSA southern Chinese adCORD pedigree including 9 affected individuals was studied. Whole-...AIMTo identify the disease-causing gene mutation in a Chinese pedigree with autosomal dominant cone-rod dystrophy (adCORD).METHODSA southern Chinese adCORD pedigree including 9 affected individuals was studied. Whole-exome sequencing (WES), coupling the Agilent whole-exome capture system to the Illumina HiSeq 2000 DNA sequencing platform was used to search the specific gene mutation in 3 affected family members and 1 unaffected member. After a suggested variant was found through the data analysis, the putative mutation was validated by Sanger DNA sequencing of samples from all available family members.RESULTSThe results of both WES and Sanger sequencing revealed a novel nonsense mutation c.C766T (p.Q256X) within exon 5 of CRX gene which was pathogenic for adCORD in this family. The mutation could affect photoreceptor-specific gene expression with a dominant-negative effect and resulted in loss of the OTX tail, thus the mutant protein occupies the CRX-binding site in target promoters without establishing an interaction and, consequently, may block transactivation.CONCLUSIONAll modes of Mendelian inheritance in CORD have been observed, and genetic heterogeneity is a hallmark of CORD. Therefore, conventional genetic diagnosis of CORD would be time-consuming and labor-intensive. Our study indicated the robustness and cost-effectiveness of WES in the genetic diagnosis of CORD.展开更多
Background: Mutations in the RPGR gene are associated with rod-cone or cone-rod dystrophy, the latter associated with mutations at the distal end. Cone-rod dystrophy (CRD) is a subgroup of hereditary retinal disorders...Background: Mutations in the RPGR gene are associated with rod-cone or cone-rod dystrophy, the latter associated with mutations at the distal end. Cone-rod dystrophy (CRD) is a subgroup of hereditary retinal disorders characterized by the primary degeneration of cone photoreceptors often followed by progressive loss of rod photoreceptors in the peripheral visual field. Purpose: The aim of this study was to describe the milder CRD phenotype associated with a novel pathogenic variant c.1905 + 223C > T (p.Q710X) found in RPGR which results in shortening of the photoreceptor specific isoform RPGR <sup>ORF15</sup>. Method: An 11-year-old boy with symptoms of CRD and two female relatives were referred for detailed ophthalmic examinations. Genetic testing was performed by next-generation sequencing of clinical exome followed by Sanger sequencing for segregation analysis. Results: Genetic analysis identified a novel variant in ORF15 of the RPGR gene (c.1905 + 223C > T, p.Q710X) in the proband considered as pathogenic according to the American College of Medical Genetics and Genomics (ACMG) standards. Segregation study identified the mutation in a heterozygous state in the mother and her sister. Detailed ophthalmological examination revealed slightly reduced color vision and scattered grayish point-like deposits in the posterior pole of the fundus in the male patient. All mutation carriers were myopic. Conclusion: We report a novel pathogenic RPGR variant in a Bulgarian patient with clinical features compatible with the CRD diagnosis. This condition is inherited as an X-linked dominant trait in its familial form presenting with a mild CRD phenotype in the male hemizygous proband and a moderate to high myopia in the female heterozygous carriers.展开更多
基金Supported by Fight Against Blindness Charity Organization
文摘AIM: To describe long term follow-up in a family with GUCY2D dominant cone dystrophy. METHODS: Optical coherence tomography scans and fundus autofluorescence images were obtained. Flash and pattern electroretinograms(ERGs) and occipital pattern reversal visual evoked potentials were recorded. RESULTS: Two members of the same family(father and son) were identified to have the heterozygous R838 C mutation in the GUCY2D gene. The father presented at the age of 45 with bilateral bull’s eye maculopathy and temporal disc pallor. Over 13 y of serial follow up visits, the bull’s eye maculopathy progressed gradually into macular atrophy. Electrophysiological tests were significantly degraded suggesting poor macular function. Spectraldomain optical coherence tomography(SD-OCT) scans showed progressive loss and disruption of the ellipsoid layer at the foveal level. His son presented at the age of 16 with bilateral granular retinal pigment epithelial changes in both maculae. Electrophysiological testing was initially borderline normal but has gradually deteriorated to show reduced cone ERGs and macula function. SD-OCT demonstrated gradual macular thinning and atrophy bilaterally. Unlike his father, there was no disruption of the ellipsoid layer.CONCLUSION: Both family members exhibited gradual changes in their fundi, electrophysiological testing and multimodal imaging. Changes were milder than those observed in other mutations of the same gene.
基金Supported by the Zhejiang Provincial Natural Science Foundation of China (No.LY12H12001)the Ningbo Key Foundation of Society Development (No.2014C50091)+2 种基金the Ningbo Natural Science Foundation (No.2012A610192)the Ningbo Yinzhou District S&T Foundation (No.YK2013-90)the Shenzhen Municipal Government of China (No.GJHZ20130417140916986)
文摘AIMTo identify the disease-causing gene mutation in a Chinese pedigree with autosomal dominant cone-rod dystrophy (adCORD).METHODSA southern Chinese adCORD pedigree including 9 affected individuals was studied. Whole-exome sequencing (WES), coupling the Agilent whole-exome capture system to the Illumina HiSeq 2000 DNA sequencing platform was used to search the specific gene mutation in 3 affected family members and 1 unaffected member. After a suggested variant was found through the data analysis, the putative mutation was validated by Sanger DNA sequencing of samples from all available family members.RESULTSThe results of both WES and Sanger sequencing revealed a novel nonsense mutation c.C766T (p.Q256X) within exon 5 of CRX gene which was pathogenic for adCORD in this family. The mutation could affect photoreceptor-specific gene expression with a dominant-negative effect and resulted in loss of the OTX tail, thus the mutant protein occupies the CRX-binding site in target promoters without establishing an interaction and, consequently, may block transactivation.CONCLUSIONAll modes of Mendelian inheritance in CORD have been observed, and genetic heterogeneity is a hallmark of CORD. Therefore, conventional genetic diagnosis of CORD would be time-consuming and labor-intensive. Our study indicated the robustness and cost-effectiveness of WES in the genetic diagnosis of CORD.
文摘Background: Mutations in the RPGR gene are associated with rod-cone or cone-rod dystrophy, the latter associated with mutations at the distal end. Cone-rod dystrophy (CRD) is a subgroup of hereditary retinal disorders characterized by the primary degeneration of cone photoreceptors often followed by progressive loss of rod photoreceptors in the peripheral visual field. Purpose: The aim of this study was to describe the milder CRD phenotype associated with a novel pathogenic variant c.1905 + 223C > T (p.Q710X) found in RPGR which results in shortening of the photoreceptor specific isoform RPGR <sup>ORF15</sup>. Method: An 11-year-old boy with symptoms of CRD and two female relatives were referred for detailed ophthalmic examinations. Genetic testing was performed by next-generation sequencing of clinical exome followed by Sanger sequencing for segregation analysis. Results: Genetic analysis identified a novel variant in ORF15 of the RPGR gene (c.1905 + 223C > T, p.Q710X) in the proband considered as pathogenic according to the American College of Medical Genetics and Genomics (ACMG) standards. Segregation study identified the mutation in a heterozygous state in the mother and her sister. Detailed ophthalmological examination revealed slightly reduced color vision and scattered grayish point-like deposits in the posterior pole of the fundus in the male patient. All mutation carriers were myopic. Conclusion: We report a novel pathogenic RPGR variant in a Bulgarian patient with clinical features compatible with the CRD diagnosis. This condition is inherited as an X-linked dominant trait in its familial form presenting with a mild CRD phenotype in the male hemizygous proband and a moderate to high myopia in the female heterozygous carriers.
