This funding opportunity announcement (FOA), through an open competition, solicits applications for Centers for Collaborative Research in Fragile X. Successful Centers will be composed of transdisciplinary teams of investigators working together to address specific scientific questions within targeted areas of research. The targeted areas of research are intended to address research gaps, drive discovery and further develop research relevant to Fragile X syndrome and (Fragile X Gene) (FMR1) Related Conditions. Targeted areas of research include: A) Advancing the understanding of the pathophysiology of FMR1 Related Conditions B) Facilitating the Development of Treatments for FMR1 Related Conditions C) Advancing the knowledge of clinical phenotypes for FMR1 Related Conditions. The Centers of Collaborative Research in Fragile X will be established using a linked U01 mechanism. Each Center will consist of 1) an administrative core and 2) three distinct but highly integrated research projects. Other shared resource cores may be proposed if appropriate to the project and goals of the proposed Center and if they fit within the budgetary constraints of the Center as a whole.