Howard Hughes Medical Institute researchers have pinpointed the genetic cause of a devastating but rare childhood disorder, called Timothy syndrome, which underlies a form of severe cardiac arrhythmia. The research shows that children who have the syndrome develop spontaneous genetic mutations that interfere with calcium channels that regulate the excitation and contraction of the heart. In defining the precise nature of the molecular abnormality, however, the researchers have also identified a class of drugs that they hope will alleviate the arrhythmia.
