NRXN1 (gene)

NRXN1 is a gene on human chromosome 2 that encodes the protein Neurexin1. Neurexins are presynaptic membrane cell-adhesion molecules that bind primarily to neuroligins, proteins that have been associated with autism. Autism is characterized by a wide range of social and cognitive deficits, which are partially attributed to faulty synaptic communication between neurons. This lack of communication is oftentimes tied to mutations in NRXN1. Structural variants of NRXN1a (neurexin1 alpha) are consistent with mutations predisposing autism. These alpha neurexins are involved in communication through coupling mechanisms of calcium channels and vesicle exocytosis, to ensure that neurotransmitters are properly released. They are specifically required for glutamate and GABA release. Implications of neurexin involvement in autism have been determined through deletion in coding exons of NRXN1a, particularly in knockout mice models. These mice showed impaired social functioning, decreased motor response in new situations, and increased aggressive behavior in males. Social functioning was of major relevance for this gene and its association with autism spectrum disorder.