Ankyrin-1 attaches (ANK1) integral membrane proteins to cytoskeletal elements. Erythrocyte ankyrins link spectrin (beta chain) to the cytoplasmic domain of the erythrocytes anion e, Xenopus/Amphibian,change protein. Defects in ANK1 are a cause of spherocytosis type 1 (SPH1), also called hereditary spherocytosis type 1 (HS1). Spherocytosis is a hematologic disorder leading to chronic hemolytic anemia and characterized by numerous abnormally shaped erythrocytes which are generally spheroidal. Inheritance can be autosomal dominant or recessive.