Pathogenic LQTS genetic variants were found in 11 fetuses (KCNQ1=8; KCNE1=1; KCNH2=1; CALM2 [calmodulin 2]=1), 9 mothers (KCNQ1=7; KCNE1=1; KCNH2=1) and 1 father (KCNQ1=1). Here, CALM2 is linked to familial long QT syndrome.