A severe brainstem involvement clinically causing REM sleep behavior disorder, stridor, respiratory insufficiency and death during sleep, cerebellar dysfunction including nystagmus and limb/gait ataxia, and autonomic dysfunction is also seen in multiple system atrophy, which is associated with alpha-synuclein accumulation in glial cytoplasmic inclusions and less frequently neuronal cytoplasmic and nuclear inclusions [8]. Here, SNCA is linked to pathologic nystagmus.