Generally variant calling programs (such as GATK-UnifiedGenotyper) look for differences between reference genome and submitted sequence. However, we all know that reference genome consist rare variants in various positions. If submitted sequence has this rare form of that variant, variant call doesn't see it and doesn't report at all. However, that variant could be very precious for analysis.
So, how can I solve this problem? What should I do to not miss that rare variants even they are in reference genome?