CASK and cask-related x-linked intellectual disability: For males, who only have a single allele of the CASK gene, the clinical presentations of patients who carried the CASK missense variants are often more severe than those of females, which are variable from mild XLID to MICPCH (Takanashi et al., 2012; Moog et al., 2015; Hayashi et al., 2017).