RESUMO
BACKGROUND: This study compared the position of the foveal center in patients with X-linked retinoschisis (XLRS) and controls and estimated the frequency of foveal ectopia in XLRS. METHOD: Fundus photographs of 23 patients with XLRS and 25 controls were reviewed. The position of the foveal center relative to the vertical center of the optic disk was determined from magnified images and expressed as the angle between the disk and foveal centers, relative to the horizontal meridian. The shortest distance between the foveal and disk centers was also measured, using the horizontal disk diameter (HDD) as the relative size unit. RESULTS: The position of the foveal center could be determined accurately for 43 eyes of the 23 patients with XLRS. The foveal center was located an average of 4.7 degrees (standard deviation, 9.3) below and 3.2 HDD (standard deviation, 0.4) temporal to the vertical disk center. In 9 (21 %) of the eyes, the fovea was above the horizontal meridian. For the control eyes, the foveal center was an average of 7.8 degrees (standard deviation, 2.3) below and 2.9 HDD (standard deviation, 0.4) temporal to the vertical disk center. According to a previous definition, foveal ectopia was present in 13 (30%) of the eyes with XLRS and none of the control eyes (P < 0.001). CONCLUSION: Foveal ectopia occurs in at least 30% of eyes with XLRS. This finding may provide a useful diagnostic sign for XLRS and may have implications for its pathogenesis.
Assuntos
Anormalidades do Olho/complicações , Fóvea Central/anormalidades , Ligação Genética , Doenças Retinianas/complicações , Cromossomo X , Fundo de Olho , Humanos , Masculino , Fotografação , Doenças Retinianas/genética , Estudos RetrospectivosRESUMO
AIMS: A number of genetic loci have been implicated in the pathogenesis of primary open angle glaucoma (POAG). The aim of this study was to identify the genetic cause of POAG in a large Scottish family and, if possible, offer genetic screening and advice to family members. METHODS: Family members were examined to determine their disease status. Base excision sequence scanning was carried out in order to test for the presence of a POAG causing mutation at known genetic loci. Direct DNA sequencing was performed in order to determine the mutation sequence. RESULTS: All family members of known affected disease status and two family members of unknown disease status were found to have a mutation in the TIGR gene. The mutation resulted in the substitution of a glycine residue with an arginine residue at codon 252 (Gly252Arg). No other sequence variations were present in any members of the family. CONCLUSION: The Gly252Arg mutation in the TIGR gene results in the development of POAG in this family. It was possible to identify younger, currently unaffected, members of the family who carry the mutation and who are therefore at a very high risk of developing POAG themselves. This is the first demonstration that Gly252Arg can be a disease causing mutation rather than a benign polymorphism. The possible pathogenic mechanisms and wider implications of the mutation are considered.
Assuntos
Testes Genéticos/métodos , Glaucoma de Ângulo Aberto/genética , Mutação/genética , Adolescente , Adulto , Idade de Início , Idoso , Substituição de Aminoácidos/genética , Feminino , Genes Dominantes , Humanos , Masculino , Pessoa de Meia-Idade , Linhagem , Penetrância , Reação em Cadeia da Polimerase , Análise de Sequência de DNAAssuntos
Anormalidades Congênitas/epidemiologia , Fertilização in vitro/estatística & dados numéricos , Gravidez Múltipla/estatística & dados numéricos , Retinopatia da Prematuridade/epidemiologia , Feminino , Humanos , Recém-Nascido de Baixo Peso , Recém-Nascido , Gravidez , Resultado da Gravidez , RiscoRESUMO
Mutations in the PAX 6 gene are known to cause many cases of inherited and sporadic aniridia. Although embryologically similar to aniridia, the cause of Peters' anomaly has received far less attention. Two reports have been published demonstrating mutations in the PAX 6 gene in Peters' anomaly. We have analysed the PAX 6 gene in 15 individuals with Peters' anomaly (7 familial, 8 sporadic). This is the largest cohort of Peters' anomaly described. The PAX 6 gene was screened using a combination of single-strand conformational polymorphism gel electrophoresis and direct sequencing. No mutations were found in the coding region of the PAX 6 gene. We feel that Peters' anomaly is a heterogeneous condition and that for the majority of cases PAX 6 is not the 'Peters' anomaly gene'.
Assuntos
Segmento Anterior do Olho/anormalidades , Proteínas de Ligação a DNA/genética , Proteínas de Homeodomínio , Mutação , Opacidade da Córnea/genética , Proteínas do Olho , Feminino , Humanos , Masculino , Fator de Transcrição PAX6 , Fatores de Transcrição Box Pareados , Linhagem , Reação em Cadeia da Polimerase , Polimorfismo Conformacional de Fita Simples , Proteínas RepressorasRESUMO
Therapeutic radiation for malignant conditions is known to cause sarcomatous change in an irradiated field after a latent period; equally this change may occur following radiotherapy to benign conditions which may result in a more difficult management problem later. Radiotherapy to benign conditions should be reserved for use after failure of conventional surgery or other interventional techniques.
