I have a vcf of dbsnp-137, and it occasionally has a GMAF info field with an allele frequency. What I don't understand is how to know which allele, ref or alt, is the minor? I've been looking at several of these by hand via ncbi, and want to know how NBCI is determining that the T is the minor allele?
from dbsnp the Alt is listed as a C.
chr1 1407372 rs188574574 T C