NLGN4X and autism: Some of the well-documented autism risk factors include genes associated with rare syndromic forms of ASD (MECP2, FMR1, and PTEN), synaptic cell adhesion and scaffolding molecules (NLGN3, NLGN4, NRXN1, CNTNAP2, and SHANK3), and genes with de novo mutations (CHD8, SCN2A, and DYRK1A among others) identified in whole-exome sequencing studies [5].