Long QT syndrome and complete situs inversus. Preliminary report of a family.

The familial long QT syndrome is a rare condition that may occur with or without deafness. Dextrocardia with complete situs inversus is a familial syndrome generally found in normal subjects with a high incidence of consanguinity among the parents. In this report we describe a Jerbian family with both disorders and with several cases of sudden death. Of 27 members of this family (3 generations) in whom ECG was performed, 15 had QT prolongation (QTc greater than 0.45). Four members (2 generations) had complete situs inversus, 3 of them also had ECG evidence of QT prolongation. The combined occurrence of these rare diseases within the same family has not been previously reported. It may be due to the high incidence of consanguinity and may raise the possibility that the loci responsible for the 2 conditions are closely related and located on the same chromosome. A more extensive study of the family is being carried out.