CYFIP2 is a component of the actin regulatory WAVE complex, which binds the fragile X messenger ribonucleoprotein (FMRP) (21–23) and has been implicated in developmental delay, epilepsy, West syndrome (a developmental and epileptic encephalopathy), and Alzheimer’s disease (23–25). This evidence concerns the gene CYFIP2 and infantile spasms.