Table 1.

Gene-level significance of DNA methylation in leukocytes in relation to dementia and Alzheimer’s disease.

		Dementia		Alzheimer’s disease
	N CpG sites	Total sample	Co-twin control	Total sample	Co-twin control
BIN1	59	0.07	0.69	0.05	0.58
HLA-DRB5	12	0.02	<0.01	0.04	0.18
SORL1	47	0.06	0.75	0.10	0.96
SLC24A4	48	0.01	0.17	0.01	0.16
ABCA7	202	0.24	–	0.23	–

Number of CpG sites included and gene-level significance for each of the five genes. Logistic regression models were applied to test associations between CpG M-vaules and dementia or Alzheimer’s disease. Models using the total sample were adjusted for age at blood sample, sex, and relatedness among twins, and co-twin control models adjusted for age at blood sample. P-values for each CpG site across the genes were combined into a test statistic using the Fisher product method, and the statistical significance tested through random permutations. Bold numbers indicate significance at the α = 0.05 level. The co-twin control permutation test for ABCA7 did not converge.