Etiology
Hereditary spherocytosis is an erythrocytic disorder of that affects the following red cell membrane proteins in a congenital fashion:

Spectrin (alpha and beta)
Ankyrin
Band-3 Protein
Protein-4.2
Lesser proteins of significanceHereditary spherocytosis can be an autosomal recessive or autosomal dominant trait. The autosomal recessive inheritance pattern accounts for close to 25% of the clinical cases. The autosomal dominant inheritance patter accounts for over 75% of the clinical cases. Many positive individuals will not present clinically, thus the etiologic data may be artificially skewed towards the more prominent dominant forms. These dominant forms tend to leave a family history that  yields generational splenectomies and black gallstones cholelithiasis. Lastly, an estimated 25% of cases are due to spontaneous mutations. Pathophysiology
Causative Genetic Mutations and Phenotypic Expressions
Hereditary spherocytosis is caused by a variety of molecular defects in the genes that code for the red blood cell proteins spectrin (alpha and beta), ankyrin, band 3 protein, protein 4.2, and other red blood cell membrane proteins:
*Online Mendelian Inheritance in Man (OMIM). The Alpha-1 refers the Alpha-1 Subunit of the Spectrin protein. The Beta refers the Beta Subunit of the Spectrin protein. These genetic mutations are acted upon and executed by erythrocyte progenitor cells within the bone marrow, where red blood cells are normally produced in the non-pathological state (see Extramedullary Hematopoiesis for pathological production outside of the bone marrow). Pathophysiology of Mutated Erythrocytic Membrane Proteins
These proteins are necessary to maintain the normal shape of a red blood cell, which is a biconcave disk.
However, the most pronounced issues with the lack of compliance and fluidity declare themselves in the failure of the erythrocyte to deform itself when transiting arterioles, capillary beds, and venules. These vessels are smaller, and can become congested or blocked altogether. Studies have demonstrated that HS is related to deep vein thrombosis (DVT) and arterial cardiovascular disease for this reason. The spleen typically acts as a filter for blood, and targets pathogens and other damaged cells within circulation. Removing blood contaminants promotes entire-body homeostasis. The following facts about the spleens role in normal body functioning are crucial to understanding the implications of HS on the overall health of the individual:

Removal of pathogens includes encapsulated bacteria, which reduces sepsis risk (see Complications below). Removal of damaged erythrocytes reduces iron burden from heme via hepatosplenic recycling, which reduces sepsis risk (see Complications below). Removal of damaged erythrocytes continues healthy signaling to bone marrow, where erythropoiesis replaces red blood cells lost to wear and tear.In relation to the three facts above, the spleen misguidedly filters spherocytes - regardless of the age or functional status of the cell. The spleen is not dysfunctional itself when selecting spherocytes for destruction, as this is the regular function of the spleen both at an anatomic structure level, and at the molecular cellular level. At the anatomic level, the passage from the Cords of Billroth into the Sinusoids may be seen as a "bottleneck", where red blood cells need to be flexible in order to pass through.