Mutations in genes encoding synaptic adhesion proteins, including neuroligin (NLGN) 3 and 4, contactin-associated protein-like 2 (CNTNAP2, Caspr2), and CADM1, are associated with autism spectrum disorder (ASD) [3]–[5]; the CADM1 mutations H246N and Y251S specifically have been found in people diagnosed with ASD who had impaired social interactions and communication, including speech and language impairments [5]. Here, CADM1 is linked to autism spectrum disorder.