DESAFIOS NA AVALIAÇÃO GENÉTICO-MOLECULAR DE PACIENTES COM SUSPEITA DA SÍNDROME DO X-FRÁGIL ATENDIDOS NA REDE PÚBLICA DE SAÚDE DO ESTADO DE GOIÁS

Abstract

The Intellectual Disability (ID) is defined as a disability characterized by significant limitations both in intellectual functioning and in the adaptive behavior and it is expressed in practical, social and conceptual skills, originating before the age of 18. It is one of the most common neuropsychiatric disorders in children and adolescents, with a 5% prevalence in our population. The Fragile X Syndrome (FXS) is the most frequent and best documented DI heritable in humans. The phenotype of FXS is associated with mutations in the gene FMR1 (Fragile X Mental Retardation-linked type 1) and it covers a broad spectrum of behavioral and physical involvement. It is caused by a CGG trinucleotide expansion in the first exon of the FMR1 gene located in the region Xq27.3 on the X chromosome Because of its phenotypic diversity, this disease has been under diagnosed in the pediatric population. Among the techniques used for molecular diagnosis of FXS, the MLPA (Multiplex Ligation-dependent Probe Amplification) has been considered promising. In this context, this study aimed to validate the molecular diagnosis of patients suspected of FXS in the Laboratory of Cytogenetics and Molecular Genetics (Lagene) by the MLPA technique. We selected 33 patients referred by medical from public health to Lagene with clinical of FXS. To perform the analysis by MLPA the Salsa MLPA P106-B1 MRX kit was used. The amplificons were obtained only for 15% of the patients. The MLPA kit used did not detect changes in the copy number of the FMR1 gene in any examined patient, being useful the need of other molecular methods to confirm the diagnosis of FXS. Thus, we concluded that such MLPA kit was not useful to detect specific changes in the copy numbers of the FMR1 gene. So the Salsa MLPA Kit P106-B1 MRX should not be used to the trial of patients with FXS.