RESUMEN: El TEA o Autismo se define como un trastorno complejo del comportamiento, caracterizado clínicamente por una tríada sintomática asociada a cambios cualitativos en la interacción social, defectos en las habilidades de comunicación y patrones de comportamiento restrictivo o estereotipado, que se manifiestan en los primeros 36 meses de vida extrauterina. Aunque el autismo se considera como una entidad definida, se subestima que los fenotipos conductuales relacionados con el autismo que forman parte de un espectro contínuo en lugar de categorías claramente definidas. El autismo se asocia hasta en un 30% a epilepsia y 80% con retraso mental, además algunos de los loci implicados en autismo son comunes a los de retraso mental. Sin embargo, las causas biológicas de ambas enfermedades aún están por definirse. Se sabe que los cambios en el número de copias de segmentos de DNA mayores de 1000 pares de bases pueden dar lugar a TEA y retraso mental (RM). En el presente estudio se utilizaron microarreglos de DNA Affymetrix GeneChip 500K mapping array para detectar cambios en el número de copias. Se encontraron 14 cambios relevantes de los cuales 10 fueron heredados y 4 de novo por lo que se consideran patogénicos. Las deleciones en 3q23, 18q21.33, y 4p16.3 fueron encontradas en 4 pacientes diferentes, siendo la región de 4p16.3 la única repetida en 2 casos.
ABSTRACT: Autism spectrum disorders are defined as a complex behavioral disease characterized by social interaction, speech delay or no speech at all and stereotyped behavior that is evident in the first 3 years of life. Even though autism is considered a mental disease by itself, autism spectrum disorders and related phenotypes form a continuous spectrum instead of clearly defined entities. Autism is associated with epilepsy in 30% of cases, as well as 80% with mental retardation. In addition, some of the loci implicated in autism are also related to mental retardation. In spite of such associations, not all biological causes are clear for both disorders and much is still to be defined. It is well known that changes in copy number in DNA regions longer than 1Kb can give place to autism spectrum disorders and mental retardation. In the present study Affymetrix GeneChip 500K arrays were used to look for changes in copy number in DNA from patients affected by both disorders. We found 14 relevant changes in copy number, 10 of them were inherited and 4 of them were not present in their parents. The latter are considered to be pathogenic changes. These deletions located at 3q23, 18q21.33, and 4p16.3 were found on four different patients. The region at 4p16.3 was found twice in different individuals, being the only region found more than once.
