Figure 5. Probabilistic Nature of LQTS Genetic Testing.

Depicted are the three major ion channels causative for LQTS with areas of probability of pathogenicity shown for mutations localizing to these respective areas. While “radical” mutations have a greater then 90% probability of being a true pathogenic mutation, the level of probability for missense mutations vary depending on their location for each channel protein. Missense mutations residing in red shaded areas have a high probability (>80%) of being pathogenic, those in blue are possibly (51–80%) pathogenic, and those in yellow shaded areas truly represent variants of uncertain significance (VUS, ≤50% probability) clinically²⁶. Figure adapted from Tester and Ackerman⁸³.