PI4K2A deficiency in an intellectual disability, epilepsy, myoclonus, akathisia syndrome.

We report a family of Saudi Arabian ancestry with two children presenting with global developmental delay, dystonia, disturbed sleep, and heat intolerance. By genome sequencing, we identified a nonsense variant in the first exon of PI4K2A that was homozygous in both affected individuals and was absent from, or heterozygous in, seven unaffected siblings. PI4K2A is highly expressed in the brain and a mouse model displays a neurological phenotype, implicating PI4K2A as a new disease gene for a neurological disorder.