Challenging behavior: Behavioral phenotypes of some genetic syndromes

Abstract

Challenging behavior in individuals with mental retardation (MR) is relatively frequent, and represents a significant obstacle to adaptive skills. The frequency of specific forms and manifestations of challenging behavior can depend on a variety of personal and environmental factors. There are several prominent theoretical models regarding the etiology of challenging behavior and psychopathology in persons with MR: behavioral, developmental, socio-cultural and biological. The biological model emphasizes the physiological, biochemical and genetic factors as the potential source of challenging behavior. The progress in the field of genetics and neuroscience has opened the opportunity to study and discover the neurobiological basis of phenotypic characteristics. Genetic syndromes associated with MR can be followed by a specific set of problems and disorders which constitutes their behavioral phenotype. The aim of this paper was to present challenging behaviors that manifest in the most frequently studied syndromes: Down syndrome, Fragile X syndrome, Williams syndrome, Prader-Willi syndrome and Angelman syndrome. The concept of behavioral phenotype implies a higher probability of manifesting specific developmental characteristics and specific behaviors in individuals with a certain genetic syndrome. Although the specific set of (possible) problems and disorders is distinctive for the described genetic syndromes, the connection between genetics and behavior should be viewed through probabilistic dimension. The probabilistic concept takes into consideration the possibility of intra-syndrome variability in the occurrence, intensity and time onset of behavioral characteristics, at which the higher variability the lower is the specificity of the genetic syndrome. Identifying the specific pattern of behavior can be most important for the process of early diagnosis and prognosis. In addition, having knowledge about behavioral phenotype can be a landmark in the creation of targeted treatment strategies for individuals with a specific genetic syndrome.