Erythrocytes are naturally a biconcave disc, which results in a larger membrane surface to volume ratio than a sphere shaped disc. These cells have the strength and flexibility needed to survive for 120 days in circulation. Their peripheral proteins stabilize the membrane and are responsible for their shape. These proteins include sprectrin, actin, ankryn, and band-4-protein. Peripheral proteins are attached to the red blood cell (RBC) membrane. Ankyrin-1 stabilizes the membrane by linking beta spectrin to band-3. The band-3-protein is part of the integral membrane and functions as an anion exchanger, glucose transporter, and water channel (Hamasaki, 1999).
A genetic disorder weakening the vertical linkage between the peripheral protein membrane and the integral protein membrane can cause reduction of membrane surface, reduction ratio of surface area to volume, and formation of spherocytes, sphere shaped RBCs. An example of this would be a weaken linkage between the band-3-protein and ankryin-1 (Perrotta, Gallagher, & Mohandas, 2008). This is a result of heterogeneous alterations in genes encode for proteins responsible for binding cite of the RBC’s inner membrane skeleton to its outer lipid bilayer. An inherited abnormality in RBC’s cause by membrane protein defects is known as Hereditary Spherocytosis (HS). The most common cause of HS is the mutations in the gene encoding the membrane protein ankyrin-1 (Gallagher, Steiner, Liem, Owen, Cline, Seidel, Garrett, & Bodine, 2010).
Hereditary Spherocytosis is the most common form of inherited hemolytic anemia in the US, northern Europe, and notably in Japan, affecting one person in 2000. HS can be found in most racial groups, but it is less common in African American and south Asia people (Perrotta, Gallagher, & Mohandas, 2008). It may be presented at any age and more severally affects individuals in the neonatal period. HS is mostly detected by incidentally when a person’s blood is tested for another reason. The hallmarks of the disease are anemia, intermittent jaundice, and splenomegaly. Spherocytes are devoid of the normal surface surplus and rigid. They are trapped during their passage through the metabolically unfavorable splenic pulp and selectively destroyed. The disease was first described in 1871 by two Belgian physicians, Vanlair and Masius as microcythemia, referring to the decreased diameter of spherocytes in the blood smear (Vanlair & Masius, 1871).
Normally no symptoms are detected, however, they can range from none to fatigue and nausea from severe anemia and jaundice. Individuals may show no signs of the disease until the contract parvovirus B19 infection leading to aplastic crisis. This causes production of RBC’s to shut down up to 10 days and the RBC count to drop to dangerously low levels. During the shutdown of erythropoiesis, patients rapidly progress anemia. This infection may expose HS in the family affected.
HS is an inherited anemic disease that is characterized by...