Table 1.

Evidence of CNS-derived cfDNA in neurodegenerative settings.

Condition	Cell or tissue of origin	DNA methylation pattern	Approach	Methodology	Reference
MS	Oligodendrocyte	Demethylation at MBP3 and unannotated region (CG10809560, Illumina annotation)	Target-specific	Bisulfite sequencing	Lehmann-Werman et al. (2016)
Cardiac arrest with brain damage	Brain	Demethylation at unannotated region (CG09787504, Illumina annotation)	Target-specific	Bisulfite sequencing	Lehmann-Werman et al. (2016)
TBI	Brain	Demethylation at unannotated region (CG09787504, Illumina annotation)	Target-specific	Bisulfite sequencing	Lehmann-Werman et al. (2016)
MS	Oligodendrocyte	Demethylation at MOG	Target-specific	Methylation-specific PCR	Olsen et al. (2016b)
ALS	Brain	Increased methylation at RHBDF promoter	Target-specific	Bisulfite sequencing	Mendioroz et al. (2018)
AD	Brain	Increased methylation at LHX2	Target-specific	Bisulfite sequencing	Pai et al. (2019)
Explosive course trainees	Neuron and glia	Differential DNA methylation in 33 regions	Multi-targeted	Bisulfite amplicon sequencing	Chatterton et al. (2021)

AD, Alzheimer’s disease; ALS, Amyotrophic lateral sclerosis; MS, Multiple Sclerosis; TBI, Traumatic Brain Injury.