CASK and Leber hereditary optic neuropathy: Other subjects with CASK null mutations that lack functional CASK protein have also been reported, and one such mutation is CASK (p.Arg27Ter) in a male patient exhibiting pontocerebellar hypoplasia, hypotonia, ventricular septal defect, optic atrophy, and intractable seizures with burst‐suppression EEG pattern (Moog et al., 2015).