Table 3.

Comparison of R_repeated and R_MZ Among the 3 Genomic Regions by CpG Content

Bins	Open Sea		Islands		Shores
Total sample	11 159 032 [0.9683]		36 957 [0.0032]		328 156 [0.0285]
n bins, study sample	683 823 (0.9458)a		1218 (0.0017)a		37 988 (0.0525)a

	Rrepeated	RMZ	Rrepeated	RMZ	Rrepeated	RMZ
Average	0.1666	0.2059	0.1857	0.2478	0.1630	0.2524
Variance	0.0044	0.0175	0.0068	0.0135	0.0036	0.0141

	Comparison
	Open Sea vs Islands		Shores vs Islands		Open Sea vs Shores
	Rrepeated	RMZ	Rrepeated	RMZ	Rrepeated	RMZ
t testb	8.06	12.56	9.50	1.35#	11.32	73.88
P value	7.6E-16	3.5E-36	2.2E-21	1.8E-01	1.1E-29	<1.0E-300

R_repeated, longitudinal correlations between the repeated methylation measurements per bin. R_MZ and R_DZ are intrapair correlations methylation levels per bin between the MZ and DZ twins.

^aPairwise comparison of the specific proportions of bins at each of the genomic regions by Z-test, or implementing χ² test to compare the distributions of bins between the sets in all cases gave statistically highly significant results, P < .001 (eg, χ² = 14 042, df = 2, P < 10⁶).

^bP values associated with t tests were all (but 1, marked by #) statistically significant at P < .001.