More importantly, the research indicates that the etiology and pathophysiology of “look-alike” conditions may be quite different, and the these heterogeneities must be identified before treatments are developed for the larger class of patients with ASD and related disorders.14 Despite the rapid advances in genetics, most clinical research has not considered genetic and individual differences by conducting “genotype-up” research studies. Instead, the studies have been “phenotype-down” research in which a broad,

Inhibitors,research,lifescience,medical behaviorally defined group of individuals are considered to establish a research sample. In many studies, all individuals with “autism spectrum Inhibitors,research,lifescience,medical disorders” are eligible for this website participation, and neuroimaging, neuropsychological tests, or other modalities are used to examine differences

between subjects with ASD and those with typical development. While this has certainly been a feasible approach, phenotypic or genotypic hetereogeneity may have washed out important clues to the pathophysiology of autism, as well as rendering it impossible to find meaningful biomarkers of autism. To Inhibitors,research,lifescience,medical address this, researchers are beginning to perform “deep phenotyping” of biological and clinical variables, as well as behavioral manifestations of ASD, in order to identify subgroups of individuals with ASD that have unique and specific biological abnormalities. Finding abnormalities in basic biologic

functions such as sleep15 and default neural networks16 among subgroups of individuals might represent new treatment targets for those individuals. Those novel therapies then could be tested in the larger Inhibitors,research,lifescience,medical ASD population for replication and generalization (or not!) In the future, clinical studies Inhibitors,research,lifescience,medical of ASD should include not only carefully characterized, homogeneous samples of ASD subjects, but also should strive to determine the specificity of the findings to autism. Comparisons against other subjects with other neurodevelopmental disorders, intellectual disabilities, communication deficits, and other symptoms will ensure that the findings are uniquely relevant to ASD. The studies could then search for genetic and nongenetic etiologies, disease modifiers, and factors conferring risk or projection. Medical treatment of ASD has been notoriously unsuccessful, almost with limited impact on the core symptoms of deficits in social reciprocity and communication and the presence of excessive restrictions of interest or behaviors. As with research into the etiology of ASD, it is possible that treatment trials have failed because they have studied heterogeneous subject groups. It is possible that greater success might result from smaller trials of more homogeneous subject groups (such as Fragile X patients or individuals with a history ol acute regression).