Table 1.

Principal characteristics of the 736 participants of the California Childhood Leukemia study and CpG sites associated with maternal smoking during gestation.

	n	%
Childhood leukemia cases	400	54.30
Male participants	439	59.60
Non-Hispanic Whites	216	30.5
Hispanics	400	54.4
White/Caucasian	132	18.6
African American	2	0.3
Native American	5	0.7
Mixed or others	245	34.6
African American	13	1.8
Native American	1	0.1
Asian or Pacific Islander	49	6.9
Mixed or others	46	6.5
Exposed to maternal smoking during gestation (self-reported by mothers)	65	8.80
	mean	sd
Gestational age (years)	39.3	2.2
Birth weight (grams)	3458.2	616.5
Age at diagnosis (years)	4.9	3.2
Top ten CpG sites most associated with exposure to maternal smoking during gestation (from Joubert et al., 2016; values from the 450 arrays are presented)	β-value
	mean	sd
cg05575921 (AHRR)	0.818	0.052
cg12803068 (MYO1G)	0.807	0.094
cg04180046 (MYO1G)	0.502	0.083
cg25949550 (CNTNAP2)	0.078	0.021
cg09935388 (GFI1)	0.749	0.109
cg14179389 (GFI1)	0.245	0.095
cg22132788 (MYO1G)	0.924	0.049
cg12876356 (GFI1)	0.786	0.123
cg18146737 (GFI1)	0.845	0.123
cg19089201 (MYO1G)	0.894	0.054