PMC3248989_01
Family Pedigree and Location of KCNH2-G816V Mutation. A) The proband is indicated by the arrow. Each individual is assigned as male (squares) or female (circles), carrying the KCNH2-G816V mutation (filled black) or those not carrying the mutation (white). Numbers below indicate QTc intervals from one or more ECGs. B) Leads V4 and II of a 12-lead ECG obtained at rest from the proband showing a prolonged QT interval. C) Schematic representation of the HERG protein topology indicating the position of residue 816 within the C-terminal cyclic-nucleotide binding domain (CNBD).
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F1
The first QTc was 483 msec (Figure 1A-B) and a second was taken after beginning a liquid diet and showed a QTc of 516 msec. The proband's mother had borderline QTc prolongation over multiple ECGs at rest, 450-472 msec (Figure 1A). Neither the father nor the two sisters showed any QTc prolongation (Figure 1A).