The features observed in all patients associated with MAG mutations included ataxia (20/20), developmental delay (12/20), dysarthria (12/20), nystagmus (16/20), spasticity (15/20), pyramidal signs (13/20), hyporeflexia (12/20), delayed gait (10/20), and neuropathy (10/20) (Table 1). The gene discussed is MAG; the disease is Global developmental delay.