Neurobehavioural evidence for the involvement of the FMR1 gene in female carriers of fragile X syndrome

► Fragile X premutation carriers were assumed to be free of any deleterious phenotype. ► We review emerging neurobehavioural profiles in female premutation carriers. ► Future studies will need to employ sensitive tasks that tap vulnerable neural networks. ► CGG thresholds may distinguish between developmental and degenerative profiles. ► Future research will lead to targeted therapeutic interventions in female carriers.