Rett Syndrome By Stephen Brian Sulkes, MD, Golisano Children's Hospital at Strong, University of Rochester School of Medicine and Dentistry Reviewed / Revised Feb 2022 | Modified Sep 2022 View Patient Education Etiology Symptoms and Signs Diagnosis Prognosis Treatment More Information Rett syndrome is a neurodevelopmental disorder occurring almost exclusively in females that affects development after an initial 6-month period of normal development.