Just to add some more detail, GEMINI requires you to annotate a VCF first with SnpEff or VEP (Ensembl). My workflow is SnpEff -> GEMINI as I prefer SnpEff's annotations and native handling of VCF in and VCF out to Annovar (Annovar has only recently added proper VCF support).
Some of the annotations SnpEff and GEMINI add that will be of interest to the OP's original question are the OMIM and ClinVar related annotations.