These summaries provide information on gene-disease associations that meet a clinical actionability threshold for pathologic variants in the gene.
In other words, ClinGen experts have compiled a list of diseases where two things are both very reliably known in their opinion: one or more mutations are known that definitely greatly increase the odds you may develop a certain disease, and, if you learn that you have one of these mutations, there is something you and your health-care providers can do, i.e. there are sensible actions to be taken now that you know you have one of these mutations (whether or not you show any signs of having the disease).
The ClinGen Actionability charts indicate the disease name and the associated genes, but they do not specify which mutations in those genes are considered pathogenic. As of early 2017, there are about 100 named genes associated with about 70 disorders.
Diseases and disorders that are on the ClinGen Actionability charts are tagged as such in SNPedia. This will allow Promethease users to quickly check their personal reports for any "actionable" genotypes, assuming the mutations have been correctly deduced and curated for the genes listed by ClinGen.