Caracterização genético/clínica de pacientes com suspeita da síndrome de Williams-Beuren (SWB) no centro- oeste brasileiro

• Autor(a) principal: Oliveira, Fernanda Ramos Barbosa de
• Data de Publicação: 2019
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Repositório Institucional da UFG
• Texto Completo: http://repositorio.bc.ufg.br/tede/handle/tede/10050
• topic: Citogenética; Síndrome de Williams-Beuren; FISH; Microdeleção; Alteração cromossômica cytogenetics; Williams-Beuren syndrome; FISH; Chromosome modifications; Microdeletion; CIENCIAS BIOLOGICAS::BIOQUIMICA

Williams-Beuren syndrome (WBS) is due to a hemizygous deletion of approximately 1.5Mb to 1.8Mb in the region of chromosome 7 (7q11.23) and causes a disease of rare and multisystem genetic profile. Typical faces, congenital heart disease, connective tissue disorders combined with learning deficit and differentiated growth, personality and cognitive profile make up the set of clinical signs that characterize SWB. Genetic etiology comprises a region of 28 single copy genes, linked to two repetitive regions (LCR - Low Copy Repeats). Molecular cytogenetic testing (fluorescent in situ hybridization or FISH) is used as the gold standard to confirm deletion of a copy of the elastin gene. Occasionally, inherited transmission to offspring is observed in an autosomal dominant manner, but there are a large number of cases due to sporadic mutations. This study included 15 patients with clinical diagnosis of WBS belonging to the WBS Goiana Association (AGSW). The clinical evaluation showed that 13 individuals (86%) had clinical characteristics for performing FISH and 2 patients (13%) did not have enough physical symptoms, fitting a dubious diagnosis for WBS. FISH demonstrated 13 patients with deletion in the elastin gene and 2 patients without this deletion, so there was agreement between the indicative clinical profile for the cytogenetic test and a positive FISH. For patients with negative FISH, we applied the technique of arrayCGH and conventional banding, which also showed no change. The present study allowed us to investigate the clinical characteristics of Brazilian Midwest patients with suspected WBS associated or not with a positive diagnosis by FISH or arrayCGH, as well as to establish the frequency of clinical signs of the syndrome. In addition, our study allowed specific coupling of newer genomic techniques with more traditional research methods, increasing the genetic understanding involved in WBS.