Assuntos
Distrofias Hereditárias da Córnea/genética , DNA/genética , Microscopia Confocal/métodos , Mutação , Microscopia com Lâmpada de Fenda/métodos , Fator de Crescimento Transformador beta1/genética , Adulto , Córnea/patologia , Distrofias Hereditárias da Córnea/diagnóstico , Distrofias Hereditárias da Córnea/metabolismo , Análise Mutacional de DNA , Humanos , Pessoa de Meia-Idade , Fator de Crescimento Transformador beta1/metabolismo , Adulto JovemRESUMO
PURPOSE: Bothnia dystrophy (BD) is an autosomal recessive retinitis pigmentosa (arRP) associated with the c.700C>T mutation in the RLBP1 gene. Testing of patients with BD has revealed the c.700C>T mutation on one or both alleles. The purpose of this study was to elucidate the underlying genetic mechanisms along with a clinical evaluation of the heterozygous patients with BD. METHODS: Patients with BD heterozygous for the RLBP1 c.700C>T were tested for 848 mutations by arrayed primer-extension technology. Further mutation detection was performed by PCR-restriction fragment length polymorphism (RFLP), sequencing, denaturing (d)HLPC and allelic discrimination. The ophthalmic examinations were performed in all c.700C>T heterozygotes. RESULTS: The clinical findings in 10 BD heterozygotes were similar to those in the homozygotes. The presence of a second mutation, c.677T>A, corresponding to p.M226K was detected in all 10 cases. Segregation analysis showed that the mutations were allelic, and the patients were compound heterozygotes [c.677T>A]+[c.700C>T]. One of those patients was also a carrier of the c.40C>T corresponding to the p.R14W change in carbonic anhydrase IV (CAIV) associated with autosomal dominant RP, RP17. His mother, a carrier of the identical change was declared healthy after ophthalmic examination. This sequence variant was found in 6 of 143 tested blood donors. CONCLUSIONS: The high frequency of arRP in northern Sweden is due to two mutations in the RLBP1 gene: c.677T>A and c.700C>T. BD is caused by the loss of CRALBP function due to changed physical features and impaired activity of retinoid binding. The CAIV p.R14W sequence variant found in one of the patients with a BD phenotype is a benign polymorphism in a population of northern Sweden.
Assuntos
Anidrase Carbônica IV/genética , Proteínas de Transporte/genética , Genes Recessivos , Heterozigoto , Mutação , Retinose Pigmentar/genética , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Alelos , Substituição de Aminoácidos , Arginina , Criança , Citosina , Feminino , Fundo de Olho , Homozigoto , Humanos , Masculino , Pessoa de Meia-Idade , Fenótipo , Retinose Pigmentar/patologia , Retinose Pigmentar/fisiopatologia , Timina , TriptofanoRESUMO
PURPOSE: To develop a systematic approach for the molecular diagnosis of retinitis pigmentosa (RP) and to report new genotype-phenotype correlations for phosphodiesterase 6 (PDE6)-based RP mutations. DESIGN: Clinical and molecular studies on a retrospective case series. METHODS: We screened 40 unrelated RP patients with an autosomal recessive RP microarray. Individuals with RP caused by PDE6 deficiency underwent genetic segregation and phenotype analysis. RESULTS: A disease-associated allele was identified in 32% of patients. Two probands (5%) had PDE6 mutations. The first proband was a compound heterozygote for known R102C and N216S alleles in PDE6A (MIM#180071). Pedigree analysis determined that the N216S variant was benign and direct sequencing discovered a novel, S303C allele. The second proband had a homozygous D600N mutation in the PDE6B gene (MIM#180072). Visual acuities of PDE6-deficient patients ranged from 20/40 to 20/200. Clinical studies showed unusual vitreomacular traction, cystoid macular edema, macular atrophy, and ring hyperfluorescence in PDE6-deficient patients. Such extensive vitreoretinal degeneration is not characteristic of photoreceptor-specific enzyme deficiencies. CONCLUSION: High-throughput deoxyribonucleic acid microarray chips can be used in combination with clinical imaging to precisely characterize patients with RP. Identifying the precise mutation in RP may become the standard of care as gene therapy emerges.
Assuntos
Nucleotídeo Cíclico Fosfodiesterase do Tipo 6/deficiência , Nucleotídeo Cíclico Fosfodiesterase do Tipo 6/genética , Mutação , Fenótipo , Retinose Pigmentar/diagnóstico , Retinose Pigmentar/enzimologia , Adulto , Idoso de 80 Anos ou mais , Alelos , Análise Mutacional de DNA , Eletrorretinografia , Proteínas do Olho/genética , Feminino , Genes Recessivos , Testes Genéticos , Genótipo , Heterozigoto , Homozigoto , Humanos , Masculino , Análise em Microsséries , Linhagem , Retinose Pigmentar/genética , Retinose Pigmentar/fisiopatologia , Estudos Retrospectivos , Acuidade VisualRESUMO
Parkin mutations account for the majority of familial and sporadic early onset Parkinson's disease (EOPD) cases with a known genetic association. More than 100 mutations have been described in the Parkin gene that includes homozygous, compound heterozygous, and single heterozygous mutations. We have designed a Parkin mutation genotyping array (gene chip) that includes published Parkin sequence variants and allows their simultaneous detection. The chip was validated by screening 85 PD cases and 47 controls previously tested for Parkin mutations. Similar genotyping microarrays have been developed for other genetically heterogeneous diseases including age-related macular degeneration. Here, we show the utility of a genotyping array for Parkinson's disease by analysis of 60 subjects from the Genetic Epidemiology of Parkinson Disease (GEPD) study that includes 15 early-onset PD case probands and 45 relatives.