MECP2 is a gene located on the X chromosome that plays a crucial role in brain development and function. It produces a protein that helps regulate the expression of other genes, particularly those involved in neuronal signaling and synaptic function. Mutations in the MECP2 gene can lead to various neurological disorders. One of the most well-known conditions associated with MECP2 mutations is Rett syndrome, a neurodevelopmental disorder primarily affecting girls. Symptoms of Rett syndrome include loss of purposeful hand skills, speech difficulties, and problems with movement and coordination. Understanding MECP2 is essential for developing potential treatments for these disorders.