SPTB and histiocytic sarcoma: It has been reported that the mutation in ANK1 (∼50%) and spectrin gene (SPTB: ∼20% and SPTA1: ∼5%) is the major cause of HS, followed by a mutation in SLC4A1 (∼15%) and EPB42 (∼10%) (An and Mohandas, 2008; Zamora and Schaefer, 2019).