MedGen, ClinVar, and the Genetic Testing Registry (GTR^®) are three interconnected NCBI databases that serve healthcare professionals as sources of medically relevant genetic information and as portals to numerous related resources:

• MedGen provides information about human disorders and other phenotypes having a genetic component (see details)
• GTR provides information on genetic tests offered by laboratories from across the world that they have voluntarily registered in GTR (see details)
• ClinVar provides information about genomic variation and its relationship to human health (see details)