column_head	description
chr 	chromosome
CpG CpG site name
cpgstart start position of CpG site
cpgend end position of CpG site
rs rsid hg19
ps base pair positions on the chromosome
allele1 minor allele
allele0 major allele
af allele frequency
beta beta estimates
se standard errors for beta
p_wald	p values from Wald test