Table 2.

Methylation Level of Blood DNA from ALS Expansion Carriers, ALS Nonexpansion Carriers, and Controls

Methylation Level (Number of Methylated CpG)	ALS Exp		ALS Nonexp		Control
	N	Frequency	N	Frequency	N	Frequency
No methylation (0)	10	0.27	63	0.98	73	0.96
Low methylation (1–3)	12	0.32	1	0.02	3	0.04
High methylation (4–26)	15	0.41	0	0.00	0	0.00
Total	37		64		76
pa: compared to ALS exp group			<0.0001		<0.0001
pa: compared to ALS nonexp group					0.625

Abbreviation is as follows: exp, expansion.

^a2-sided Pearson χ² test was used, df = 2. Fisher’s exact test was used (when expected value < 5).