Project Summary/Abstract – Clinical Genome Resource Project ClinGen's critical questions involve determining the clinical validity of gene-disease associations, the pathogenicity of variants in clinically relevant genes, and the actionability of genomic information. These questions are addressed in the aims of this section. In addition, since the scope of this project is to eventually provide curated information about all clinically relevant genes and variants, it is necessary to establish a strong ecosystem of expert curation groups who have the domain knowledge to make authoritative assertions. This section will detail the development and expansion of the Clinical Domain Working Groups and their phenotypic sub-groups for expert curation of genes and variants.