Estudo da ocorrência de biomarcadores da instabilidade do genoma na mucosa oral em crianças com Síndrome de Down

Abstract

Down Syndrome (DS) is a complex genetic and metabolic alteration attributed to the presence of three copies of chromosome 21. The one more chromosome in this syndrome generates a phenomenon known as genome instability. This instability is characterized by increased occurrence of damage to genetic material and the ineffectiveness of nuclear repair machinery. It can be evaluated through the buccal micronucleus cytome assay (BMCyt), in which the presence of cells that indicate the occurrence of cell death, necrosis, gene amplification, induction of apoptosis and failure in cytokinesis are observed. The objective of this work was to evaluate the frequency of biomarkers of genome instability in children with DS and to compare with non-syndromic children. In all, 30 children of both sexes (16 boys and 14 girls) participated in the study, according to the prior authorization of their parents. Biomarkers of genome instability have been found which have no occurrence in the literature of their presence in the oral mucosa through BMCyt, being: cells with circular nucleus, nucleus in kidney and nuclear fusion. In addition, Spearman correlation results showed a significance between bud cells and micronucleus cells, binucleate cells and cells with buds, binucleate cells and fused nucleus (p <0.05). Finally, it was observed that children with DS have a higher occurrence of these cellular markers compared to other individuals in a typical population. This result may be related to the entire systemic genotoxic potential, including the clinical, nutritional and biochemical status of the individuals. Therefore, genome instability in children with DS suggests that the genotoxic events visibly found through the biomarkers, depict not only aneuploidy but all the exposed state they are exposed to.