IQSEC2 mutations in ID patients which affect the PH domain of the protein have also been reported, including a p.L992X change in a patient with schizophrenia (Purcell et al., 2014), a de novo p.Q1033X mutation in a male with severe ID, epilepsy, strabismus and autistic features (Redin et al., 2014), and a de novo mutation (p.R1055X) in a female with severe ID, epilepsy and borderline macrocephaly (Tzschach et al., 2015). This evidence concerns the gene IQSEC2 and Strabismus.