What are the genetic changes related to Romano-Ward syndrome ?
Mutations in the KCNE1, KCNE2, KCNH2, KCNQ1, and SCN5A genes cause Romano-Ward syndrome. These genes provide instructions for making proteins that act as channels across the cell membrane. These channels transport positively charged atoms (ions), such as potassium and sodium, into and out of cells. In cardiac muscle, ion channels play critical roles in maintaining the heart's normal rhythm. Mutations in any of these genes alter the structure or function of these channels, which changes the flow of ions between cells. A disruption in ion transport alters the way the heart beats, leading to the abnormal heart rhythm characteristic of Romano-Ward syndrome.  Unlike most genes related to Romano-Ward syndrome, the ANK2 gene does not provide instructions for making an ion channel. The ANK2 protein, ankyrin-2, ensures that certain other proteins (particularly ion channels) are inserted into the cell membrane appropriately. A mutation in the ANK2 gene likely alters the flow of ions between cells in the heart, which disrupts the heart's normal rhythm. ANK2 mutations can cause a variety of heart problems, including the irregular heartbeat often found in Romano-Ward syndrome. It is unclear whether mutations in the ANK2 gene cause Romano-Ward syndrome or lead to another heart condition with some of the same signs and symptoms.