This gene is composed of 2 exons and codes for an integral membrane protein that is an inward-rectifier type potassium (Kir) channel, which is controlled by G-proteins. This protein is voltage-dependent, and as extracellular levels of potassium rise, normaly functioning protein allow for repolarization. Mutations in this gene have been associated with Sudden Infant Death syndrome (SIDS), J-wave syndromes and other disorders characterized by early repolarization.