Click on image to view larger version.

Figure 1 Compound pedigree of families 041 and 090. Index family (referred to as 041090 in text) consists of subjects II/8, II/13, III/5, III/6 and III/7. Available corrected QT values (QTc, in ms) are shown under individual symbols. The medication may have affected the QTc values of subjects I/2 and I/4. In addition, subject II/3 has left bundle branch block in the electrocardiogram (ECG), which prolongs the QTc interval (values shown in parentheses). Neither the sample for DNA analysis nor the ECG was available from subjects marked by an asterisk. Open circles/squares = female/male mutation noncarriers; half-filled symbols = L552S heterozygotes; and filled symbols = L552S homozygotes.