Genetic screening to determine an etiologic diagnosis in children with mental retardation Búsqueda de afecciones genéticas como etiología de déficit intelectual en individuos que asisten a escuelas de educación especial

Abstract

Mental retardation or intellectual disability affects 2% of the general population, but in 60% to 70% of cases the real cause of this retardation is not known. An early etiologic diagnosis of intellectual disability can lead to opportunities for improved educational interventions, reinforcing weak areas and providing a genetic counseling to the family. Aim: To search genetic diseases underlying intellectual disabilities of children attending a special education school. Material and methods: A clinical geneticist performed the history and physical examination in one hundred and three students aged between 5 and 24 years (51 males). A blood sample was obtained in 92 of them for a genetic screening that included a standard karyotype, fragile X molecular genetic testing, and search for inborn errors of metabolism by tandem mass spectrometry. Results: This approach yielded an etiological diagnosis in as much as 29 patients. Three percent of them had a fragile X syndrome. Inborn errors of me