Rett Syndrome, Congenital Variant, also known as rett syndrome congenital variant, is related to noonan syndrome 1, and has symptoms including athetosis, constipation and muscle spasticity. An important gene associated with Rett Syndrome, Congenital Variant is FOXG1 (Forkhead Box G1). Affiliated tissues include tongue and eye, and related phenotypes are global developmental delay and intellectual disability, severe