RESUMO
PURPOSE: Schnyder crystalline corneal dystrophy (SCCD; MIM 121800) is a rare autosomal dominant disease characterized by an abnormal increase in cholesterol and phospholipid deposition in the cornea, leading to progressive corneal opacification. Although SCCD has been mapped to a genetic interval between markers D1S1160 and D1S1635, reclassification of a previously unaffected individual expanded the interval to D1S2667 and included nine additional genes. Three candidate genes that may be involved in lipid metabolism and/or are expressed in the cornea were analyzed. METHODS: DNA samples were obtained from six families with clinically confirmed SCCD. Analysis of FRAP1, ANGPTL7, and UBIAD1 was performed by PCR-based DNA sequencing, to examine protein-coding regions, RNA splice junctions, and 5' untranslated region (UTR) exons. RESULTS: No disease-causing mutations were found in the FRAP1 or ANGPTL7 gene. A mutation in UBIAD1 was identified in all six families: Five families had the same N102S mutation, and one family had a G177R mutation. Predictions of the protein structure indicated that a prenyl-transferase domain and several transmembrane helices are affected by these mutations. Each mutation cosegregated with the disease in four families with DNA samples from both affected and unaffected individuals. Mutations were not observed in 100 control DNA samples (200 chromosomes). CONCLUSIONS: Nonsynonymous mutations in the UBIAD1 gene were detected in six SCCD families, and a potential mutation hot spot was observed at amino acid N102. The mutations are expected to interfere with the function of the UBIAD1 protein, since they are located in highly conserved and structurally important domains.
Assuntos
Arco Senil/genética , Cromossomos Humanos Par 1/genética , Distrofias Hereditárias da Córnea/genética , Mutação , Proteínas/genética , Proteína 6 Semelhante a Angiopoietina , Proteínas Semelhantes a Angiopoietina , Angiopoietinas , Fatores Biológicos/genética , Proteínas de Transporte/genética , Análise Mutacional de DNA , Dimetilaliltranstransferase , Feminino , Genes Dominantes , Humanos , Masculino , Linhagem , Fosfotransferases (Aceptor do Grupo Álcool)/genética , Reação em Cadeia da Polimerase , Análise de Sequência de DNA , Serina-Treonina Quinases TORRESUMO
PURPOSE: It was the aim of this study to evaluate antiphospholipid antibodies (APA), i.e. lupus anticoagulants (LA) and anticardiolipin (ACA) IgG and IgM, in ophthalmic occlusive disease. METHODS: Over a 3.5-year period, APA were evaluated in 368 patients. RESULTS: Eighty-six patients (23.4%), compared to 5% in the general population, tested positive for APA. APA did not differ significantly between patients with venous (20.6%) or arterial (25.5%) occlusive disease. This included 93 patients with central retinal vein occlusion (18% APA positive), 67 with retinal branch vein occlusion (24% APA positive), 41 with central retinal artery occlusion (22% APA positive), 53 with retinal branch artery occlusion (32% APA positive), 71 with anterior ischemic optic neuropathy (23% APA positive), 12 with posterior ischemic optic neuropathy (33% APA positive) and 31 patients with amaurosis fugax (23% APA positive). Excluding patients with accepted main risk factors, APA were positive in 15.3% of 85 patients. CONCLUSION: The high APA prevalence confirms its relevance in ocular occlusive disorders.
