Estimativa da frequência da inversão SWBinv-1 entre pais de portadores ds síndrome de Williams-Beuren e pais de filhos normais do Brasil

• Ano de defesa: 2014
• Autor(a) principal: Loaiza Medina, Juan Diego [UNESP]
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Estadual Paulista (Unesp)
• Palavras-chave em Português: Williams, Síndrome de; Pais e filhos; Citogenetica humana; Hibridização in situ; Aconselhamento genetico; Genetic counseling; Williams syndrome
• Link de acesso: http://hdl.handle.net/11449/123278; http://www.athena.biblioteca.unesp.br/exlibris/bd/cathedra/06-05-2015/000827183.pdf

The Williams-Beuren syndrome (WBS) is a rare genetic disorder characterized by various physical abnormalities, including facial dimorphisms, cardiovascular abnormalities, intellectual disability and growth characteristic cognitive profile and occasionally transient infantile hypercalcemia, with a prevalence of 1/7500 . The etiology of SWB is a hemizygous deletion of contiguous genes at chromosome region 7q11.23. The most common sizes of deletions are 1.5 and 1.8 Mb and encompass 28 genes. The mechanism of deletion is directly linked to repetitive chromosomal regions, called Low Copy Repeats (LCR). These repetitive regions are distributed throughout the genome, constituting about 5% of its total and are the substrate for chromosomal recombination (crossing-over) during the meiotic process. In some instances the process of recombination can occur unevenly among homologous non-allelic (homologous recombination nonallelic - NAHR), which can result in deletion, duplication or inversion of a gene or more genes. Balanced inversions can result in a hemizygous polymorphism has been found that the critical region for this inverted SWB (SWBinv-1) with greater frequency among parents of individuals with WBS. Published data suggest that individuals inversion SWBinv-1 has a 22-25% chance of having a child with SWB, compared with the general population (5.8%). We we developed a strategy for screening potential carriers SWBinv-1, among the parents of individuals with WBS, so we can check the frequency of this inversion in both parents of children with SWB as between parents of children without SWB in Brazil. Thus analyzes of interphase nuclei were performed on blood smear by technique hybridization in situ by fluorescence (FISH) analysis and compared to metaphase and interphase lymphocyte culture. Were part of the sample group and 38 couples in the control group 20 couples. Of the 38 couples in the sample group ...