The Lab for Neurobehavioral Development conducts studies of individuals over 40 years of age who are carriers of the FMR1 gene. Full mutations of the FMR1 gene cause Fragile X Syndrome, and premutations of this gene have been found to be associated with other neurological and medical conditions in some individuals. Fragile X-associated Tremor/Ataxia Syndrome (FXTAS) is a neurodegenerative disorder that affects a portion of FMR1 premutation allele carriers as they age. We currently are conducting studies to examine neurological, motor and cognitive abilities in FMR1 premutation carriers over age 40 years. These studies also utilize magnetic resonance imaging (MRI) to examine structural and functional brain alterations associated with FMR1 premutations.