Description of columns

snp: SNP in the following format Chromosome:Genomic coordinate_Reference allele_Alternative allele 
chr: Chromosome number
bp: Genomic coordinate based on hg19 assembly
ref: Reference allele
alt: Alternative allele
minor: Minor allele in the study population
major: Major allele in the study population
maf: Minor allele frequency
beta: Effect size in association analysis (years / minor allele)
se: Standard error
pval: P-value