As exemplified by CNTNAP2 and NRXN1 gene, heterozygous missense variants confer susceptibility to autism [54, 55] while compound heterozygous mutations of CNTNAP2 and NRXN1 cause Pitts-Hopkins like syndrome [56]. Here, NRXN1 is linked to Pitt-Hopkins or Pitt-Hopkins-like syndrome.