Meiotic instability of the pathogenic expansion (CAG)n=38 of the HTT gene in a familial case of Huntington´s disease.
Introduction: Huntington's disease (HD) is an autosomal dominant neurodegenerative disorder, with progressive loss of striatal neurons, characterized by choreic movements, cognitive deterioration and psychiatric disturbances. HD is caused by the pathogenic expansion of the unstable trinucleotid...
| Autores: | , , , |
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| Tipo de recurso: | artículo |
| Estado: | Versión publicada |
| Fecha de publicación: | 2010 |
| País: | Brasil |
| Institución: | Faculdade de Medicina de Campos (FMC) |
| Repositorio: | Revista Científica da Faculdade de Medicina de Campos |
| Idioma: | portugués |
| OAI Identifier: | oai:ojs.www.fmc.br:article/114 |
| Acceso en línea: | https://www.fmc.br/ojs/index.php/RCFMC/article/view/114 |
| Access Level: | acceso abierto |
| Palabra clave: | análise de segregação, distúrbio de repetição trinucleotídica doença de Huntington expansão de repetição trinucleotídica CAG poliglutamina teste genético Genetic test Huntington disease polyglutamine trinucleotide repeat disorder trinucleotide repeat expansion CAG segregation analysis |
| Sumario: | Introduction: Huntington's disease (HD) is an autosomal dominant neurodegenerative disorder, with progressive loss of striatal neurons, characterized by choreic movements, cognitive deterioration and psychiatric disturbances. HD is caused by the pathogenic expansion of the unstable trinucleotide repeat (CAG)n in exon 1 of the huntingtin HTT gene. The symptoms generally manifest at late age (35-50years), and there is a significant inverse correlation between the threshold number of CAG repeats and the time of onset of symptoms.Objectives: To screen for alleles with expanded (CAG)n repeats in a nuclear family with clinical suspicion of HD, by meiotic segregation analysis, and to assist genetic counseling.Methods: Four adults (father, daughter 1, son and daughter 2) were included in the study, being father and son referred because of clinical findings suggestive of HD and the daughters asymptomatic.The (CAG)n alleles were determined by a specific quantitative fluorescent polymerase chain reaction assay.Results: Genotyping of (CAG)n alleles showed that the father, son and both daughters carried pathogenic alleles with 38, 45, 40 e 41 CAG repeats, respectively.Conclusion: Segregation analysis of (CAG)n alleles revealed paternal carrier transmission of the pathogenic unstable expansion (CAG)n=38 to the son and both daughters. Aiming at early and adequate genetic counseling in the daughters, the genetic test allowed identifying the pathogenic alleles in a rapid and precise manner. |
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