NLGN4X (Neuroligin 4 X-Linked) is a Protein Coding gene. This gene encodes a member of the type-B carboxylesterase/lipase protein family. The encoded protein belongs to a family of neuronal cell surface proteins. NLGN4X interacts with discs large homolog 4 (DLG4). It is broadly expressed in the brain, ovary, and other tissues. Genetic mutations in NLGN4X, including point mutations and copy number variants (CNVs), have been associated with susceptibility to autism spectrum disorders (ASDs). Pathogenic mutations in the NLGN4X gene in ASDs and/or mental retardation (MR) are rare. Based on in vitro models, NLGN4X knockdown directly impacts the neurodevelopmental process during the formation of neurons and their connections.