I'm completing a variant analysis of rare variants found in the genomes of my cases vs. controls. I'm only looking at rare variants (variants where the alternate allele is present in less than 1% of the population, as determined by the 1000 genomes project alternate allele frequency). However, some of my variants (including many that have rsID #s) don't have an estimated 1000 genomes project allele frequency in dbSNP. For example, rs61867532 doesn't include estimated allele frequencies in the population:
Why might a variant have an rsID number but no estimated allele frequencies for the population based on 1000 genomes project data? Usually when you look up a SNP in dbSNP you can find the estimated allele frequency for the population.