| A rare genetic neurological disorder with characteristics of hypomyelination of early myelinating structures such as the brainstem, cerebellar white matter, optic radiation, and periventricular white matter, while structures acquiring myelin later are better myelinated. Patients present in infancy with nystagmus, developmental delay, and progressive ataxic-spastic or ataxic syndrome. Cognitive functions are normal or only mildly impaired. |