Dr. Huda Zoghbi’s work has provided insight into Autism Spectrum Disorders (ASD) by focusing on Rett Syndrome, a postnatal progressive neurological disorder. By studying the genetics of Rett Syndrome, her group made the seminal discovery of X-linked Methyl CpG-binding protein 2 (MECP2) as the gene that causes Rett Syndrome. Zoghbi’s group showed that the severity of the disease was highly dependent on the amount of functional MeCP2 protein expressed. Females, who carry one normal and mutant MECP2 allele typically suffer from Rett syndrome, but the amount of functional protein is influenced by X-chromosome inactivation, and girls with more cells expressing normal allele have milder features. Surprisingly, they also showed that duplications spanning MECP2 can cause a Rett-like progressive neurological disease, highlighting the importance of MeCP2 levels for neural functions. Zoghbi describes how these findings have spurred new research into how MeCP2 affects postnatal development and brain function.