Our research program is focused on the structure, function, pharmacology, and molecular genetics of ion channels. His laboratory has contributed greatly to understanding the mechanisms by which ion channel mutations cause a variety of inherited disorders of membrane excitability including congenital cardiac arrhythmia susceptibility and epilepsy. These basic and translational investigations have provided many opportunities to investigate the relationship between structure and function in ion channels and have helped establish important genotype-phenotype correlations for several human diseases and certain animal models. We were first to elucidate the functional consequences of an ion channel mutation linked to an inherited cardiac arrhythmia (Long-QT Syndrome). This discovery contributed greatly to understanding arrhythmia susceptibility in the disease and inspired use of drugs targeting persistent sodium current as a therapeutic strategy. Recently, the use of exome sequencing enabled us to discover human calmodulin mutations in congenital arrhythmia syndromes. Our studies of the molecular basis for genetic epilepsy have revealed new targets for antiepileptic drug development.