J. Tester DJ, Bombei HM, Fitzgerald KK, et al. - In this study, researchers explored the underlying cause of multiple sudden deaths in young individuals and sudden cardiac arrests that occurred in 2 large Amish families. They enrolled two large extended Amish families with multiple sudden deaths in young individuals and sudden cardiac arrests. They distinguished a novel homozygous multiexon duplication in RYR2 young Amish individuals with exertion-related sudden deaths and sudden cardiac arrests without an overt phenotype to suggest RYR2-mediated catecholaminergic polymorphic ventricular tachycardia. They demonstrated that identification of unaffected heterozygous carriers may serve potentially lifesaving premarital counseling and reproductive planning, considering that no cardiac tests reliably distinguish at-risk patients, and given the high rate of consanguinity in Amish families.