The neuroligin 3 gene (NLGN3) encodes a cell-adhesion protein present on the postsynaptic side of the synapse, and it has been implicated in the organization and remodeling of neuronal synapses. The NLGN3 gene is located at Xq13 and contains 7 exons. One missense mutation (R451C) in NLGN3 has been reported in a Swedish family with two affected male siblings, one with classical autism and the other with Asperger syndrome (Jamain S et al. Nat Genet. 2003;34:27-29).