ATRX and X-linked non-syndromic intellectual disability: Similarly, mutations in ATRX (alpha-thalassemia/mental retardation, X-linked) cause the alpha-thalassemia X-linked intellectual disability syndrome, and acquired mutations have been observed in multiple types of cancers like gliomas (Stevenson, 2000); SOX5 [sex determining region Y (SRY)-related high mobility group (HMG) box family of proteins] is also known for intellectual disabilities (Lamb et al., 2012; Schanze et al., 2013) and dysregulation of chondrogenesis (C-F.