KCND3 (Potassium Voltage-Gated Channel Subfamily D Member 3): KCND3 encodes a voltage-gated potassium channel protein that is primarily expressed in the heart and brain. These channels play a crucial role in regulating the electrical activity of cells, including cardiac and neuronal cells. Mutations in KCND3 have been associated with certain cardiac arrhythmias and neurodevelopmental disorders....