KCNJ2 and cardiac arrhythmia: One possible DMS approach is to adapt yeast-based functional assays that demonstrate normal and LoF variants based on growth patterns, which have been reported for ATS-associated Kir2.1 (73) and Barter Syndrome-associated Kir1.1 (a Kir2.1 paralog that is not arrhythmia related) (81).