5-methylcytosine and 5-hydroxymethylcytosine in brains of patients with multiple system atrophy and patients with Parkinson's disease.

Multiple system atrophy (MSA) is a sporadic neurodegenerative disorder of unknown etiology, characterized pathologically by α-synuclein aggregates preferentially found in oligodendroglial cells. DNA methylation has emerged as a mechanism of regulation of α-synuclein expression. Reduced 5-methylcytosine (5-mC) DNA methylation of α-synuclein has been found in the brains of patients with Parkinson's disease (PD).