However, the infant with the KCNE1 mutation, who was the subject of the aforementioned case report by Huang et al. [191], was also the carrier of a spontaneous mutation in SCN5A that may provide a more likely explanation for her death, given that her father was found to be a carrier of the KCNE1-T20I mutation with no LQTS-related phenotype [191]. This evidence concerns the gene KCNE1 and familial long QT syndrome.