We suspected the association of GPR143 with strabismus in patient 1, but a family proband with strabismus revealed a 7.7-Mb deletion within Xp22.2–Xp22.3 that did not encompass GPR143. Mutation of NLGN4X is associated with intellectual disability (OMIM: 300495), X-linked Asperger syndrome type 2 (OMIM: 300497), and autism (Daoud et al., 2009; Shi et al., 2013). Here, NLGN4X is linked to Intellectual disability.