ABCB6 encodes a member of the ABC protein superfamily; ABC proteins are involved in the transport of various substrates across cell and organelle membranes. ABCB6 belongs to the Multi-Drug Resistance and Transporter associated Antigen Processing (MDR/TAP) family, one of 7 ABC families. The ABCB6 transmembrane protein is thought to function on the outer membrane of mitochondria and facilitate ATP-dependent uptake of porphyrin. Among its associated functions include heme biosynthesis, binding, and transport, as well as cellular iron ion homeostasis and brain development. Recent studies indicate ABCB6 localizes to the plasma membrane where it functions in drug transport and resistance and additionally forms the Langereis (Lan) blood antigen group present on red blood cells.
ABCB6 deficiency is the cause of multiple disorders including autosomal dominant (AD) pigmentary genodermatosis; AD isolated microphthlamia with coloboma; AD pseudohyperkalemia; as well as autosomal recessive deficiency resulting in an absence of Lan antigens on RBCs.