Exome sequencing helped the fine diagnosis of two siblings afflicted with atypical Timothy syndrome (TS2)

Background Long-QT syndrome(LQTS) causes a prolongation of the QT-intervalin the ECG leading to life threatening tachyarrhythmia and ventricular fibrillation. One atypical form of LQTS, Timothy syndrome(TS), is associated with syndactyly, immune deficiency, cognitive and neurological abnormalities as well as distinct cranio-facial abnormalities.