The Long QT Syndrome (LQTS) is an infrequently occurring disorder of unknown cause in which affected individuals have an unusual electrocardiographic repolarization abnormality and a propensity to syncope and fatal ventricular tachyarrhythmias. The first family with LQTS was described by Jervell and Lange-Nielsen in 1957. Three sudden deaths occurred in four deaf children with QT prolongation; two other children and the parents were healthy with normal hearing and normal electrocardiograms. The findings were interpreted as a pattern of autosomal recessive inheritance. Subsequent reports identified LQTS families with normal hearing (Romano-Ward Syndrome) having a pattern of occurrence suggesting autosomal dominant inheritance.