The E1784K mutation in SCN5A is associated with mixed clinical phenotype of type 3 long QT syndrome
J. Clin. Invest. Naomasa Makita, et al. 118:2219 doi:10.1172/JCI34057 [Go to this article.]

Figure 1
Pedigrees of E1784K families. Pedigrees of 15 LQT3 families (pedigrees A–O shown in panels A–O, respectively) carrying E1784K are shown. The pedigree C was previously reported elsewhere (17). Probands are indicated by an arrow. Nine symptomatic mutation carriers, shown by the filled symbols, had episodes of syncope (n = 8) and unexplained palpitations (n = 1; B;II:2). Asymptomatic mutation carriers (n = 32) are shown as symbols with a dot, and gray symbols are the individuals with QT prolongation who declined genetic testing, or are sudden cardiac death victims (SCD; A;II:6 and C;III:1) whose DNA was not available. Individuals exhibiting ST elevation in the right precordial leads are depicted with an asterisk. N represents individuals genetically undetermined. S, P, and C represent individuals who had sinus node dysfunction (n = 16), permanent pacemaker implantation (PPM; n = 4), and an implantable cardioverter defibrillator (ICD; n = 4), respectively. Values for QTc intervals are given beneath each symbol. The Na channel provocation test was positive in individuals with + (A;II:1, A;III:8, A;III:9, E;II:3, and K;II:1), and negative in the individuals with – (A;II:3, E;I:2, E;II:2, and N;II:1). In family G, V1098L was identified in II:2 (who also had E1784K) but not in I:2 (an E1784K carrier), showing that II:2 was a compound SCN5A mutation carrier. In family H, parents of the proband were both genetically unaffected, indicating that E1784K in the proband was most likely a de novo mutation. Three asymptomatic family members with a prolonged QTc (D;I:1, D;II:2, and G;II:1) declined genetic testing, and 1 individual, D;I:1, exhibited sinus node dysfunction. Squares and circles indicate men and women, respectively.