All of the following are features of Timothy syndrome except:
a) CACNA1C mutation
b) Named after Katherine W. Timothy
c) Phase 1 of action potential is affected by gene mutation
d) Multisystem disorder
Correct answer: c) Phase 1 of action potential is affected by gene mutation
Cav1.2 calcium channel is affected by CACNA1C mutation in Timothy syndrome. This channel is important in the phase 2 (plateau phase) of cardiac action potential. Timothy syndrome is characterised by marked prolongation of QT interval, syndactyly, congenital heart disease, cognitive abnormalities, and intermittent hypoglycemia. It is designated as LQT8.
Timothy syndrome – Cardiology MCQ
