International CRDS Registry

CRDS Cohort Inclusion Criterion: \- Presence of a rare\* RYR2 variant that is characterized to be loss-of-function based on in vitro testing# RYR2 Truncating and Large CNV Cohort Inclusion Criterion: \- Presence of a rare\* RYR2 truncating variant and/or large copy number variant involving the RYR2 gene. Carriers of a Non-Functional RYR2 variant Inclusion Criterion: \- Presence of a rare\* RYR2 variant that is characterized to be neither loss- nor gain-of-function based on in vitro testing# \*rare defined as gnomAD prevalence \< 0.1% #RYR2 in vitro functional testing will be performed in the laboratory of Dr. Wayne Chen (University of Calgary)