Diagnostic algorithm for the characterization of telomerase variants. Variants are considered disease-causing if they have been reported in other unrelated patients or cause LOF. Conversely, variants are considered bystanders if they appear on ExAC or if a different disease gene has been identified. Additionally, a variant is classed as a bystander if it does not segregate with all affected members of a family. If segregation of the variant is unknown (or if a patient is a sporadic case) and if TRAP activity is >5% or unknown, a variant should be considered as status uncertain.