Required for gap junction formation (Probable). Required, with CNTNAP1, for radial and longitudinal organization of myelinated axons. Plays a role in the formation of functional distinct domains critical for saltatory conduction of nerve impulses in myelinated nerve fibers. Demarcates the juxtaparanodal region of the axo-glial junction. Interacts (via C-terminus) with KCNA2. Expressed in the juxtaparadonal region. Predominantly expressed in nervous system. Disease susceptibility is associated with variants affecting the gene represented in this entry. A chromosomal aberration involving CNTNAP2 is found in a patient with autism spectrum disorder. Paracentric inversion 46,XY,inv(7)(q11.22;q35). The inversion breakpoints disrupt the genes AUTS2 and CNTNAP2. The disease is caused by variants affecting the gene represented in this entry. Belongs to the neurexin family. Extended N-terminus.