ATP1A3 and hereditary cerebellar ataxia: The 7 genetic/metabolic disorder cases all had preceding respiratory infections within 1 week and included late-onset methylmalonic acidemia (3 cases), biotinidase deficiency (1 case), Leigh syndrome (1 case), hereditary cerebellar ataxia with ATP1A3 mutation (1 case), and adrenoleukodystrophy (1 case).