RYR2 and familial long QT syndrome: The findings of a mutation in RYR2 among 8% of the selected cases, as well as CNVs among 2% of all genotype-negative cases suggest that mutation analysis of RYR2 and MLPA analysis in a genotype-negative LQTS population is of importance and might give a higher yield than screening of the less common LQTS-associated genes.