More than 80% of ASD has high heritability,17 and several risk genes, such as NLGN3, MECP2, SHANK2, SHANK3, ARID1B, CHD8, and ASH1L, have been demonstrated to be genetically linked with ASD.18, 19, 20, 21, 22, 23, 24, 25 Among these, contactin-associated protein-like 2 (CNTNAP2) and CNTNAP4 are susceptible genes, and mutation or deletion of these genes lead to autism-like phenotypes.26, 27, 28 As a transmembrane protein member of the neurexin superfamily, Cntnap4 is involved in neuron–glia interaction and is critical for neurological development and synaptic function.29 The gene discussed is CNTNAP4; the disease is autism.