Hereditary spherocytosis is a genetically transmitted form of anemia where red blood cells are sphere-shaped rather than disk-shaped, making them prone to hemolysis. Symptoms include fatigue, pallor, jaundice, and in acute cases hypoxemia and hyperbilirubinemia. Diagnosis involves observing the lack of central pallor in red blood cells and increased fragility in hypotonic solutions. The condition is caused by defects in genes coding for membrane proteins, preventing red blood cells from maintaining their disk shape and surviving passage through the spleen. Treatment options include blood transfusions, folic acid supplementation, and splenectomy.

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Hereditary spherocytosis
Hereditary spherocytosis is a genetically-transmitted (autosomal dominant) form
of spherocytosis, an auto-hemolytic anemia characterized by the production of
red blood cells that are sphere-shaped rather than bi-concave disk shaped
(Donut-Shaped), and therefore more prone to hemolysis Howell-Jolly bodies may
be seen.
Symptoms
The spleen's hemolysis results in anemia and hyperbilirubinemia
Symptoms of fatigue, pallor, and jaundice.
Acute cases show hypoxemia through anemia
Acute kernicterus through hyperbilirubinemia
The disease will not be noticed until the child is about 4 or 5 years of age.
Chronic symptoms include anemia, increased blood viscosity, and splenomegaly,
unconjugated or indirect bilirubin
Pigmented gallstones or "sludge" to develop.
In chronic infection there is an increase in the destruction of RBC, resulting in the
appearance of acute symptoms, a hemolytic crisis.
Spherocytosis patients who are heterozygous for a hemochromatosis gene may
suffer from iron overload despite the hemochromatosis genes being recessive
Diagnosis
1. RBC lacking the central pallor as seen in non-hereditary spherocytosis is
typically more marked in hereditary spherocytosis.
2. Other protein deficiencies cause hereditary
elliptocytosis, pyropoikilocytosis or stomatocytosis.
3. iron overload may be a significant problem

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Measuring iron stores is therefore considered part of the diagnostic approach
to hereditary spherocytosis.
4. osmotic fragility test
In this test, the spherocytes will rupture in mildly hypotonic solutions - this is
due to increased permeability of the spherocyte membrane to salt and water.
Pathophysiology
 Hereditary spherocytosis is an autosomal dominant or recessive trait
 25% of cases due to spontaneous mutations.
 A patient has a 50% chance of passing the mutation onto his/her offspring.
 Hereditary spherocytosis is caused by a variety of molecular defects in the
genes that code for spectrin (alpha and beta), ankyrin, band
3 protein, protein 4.2, and other erythrocyte membrane protein that is most
commonly defective is ankyrin which responsible for incorporation and
binding of spectrin, spherocytes.
 Erythrocytes need to be flexible in order to pass through. In hereditary
spherocytosis, erythrocytes fail to pass through and get phagocytosed,
causingextravascular hemolysis.
Complications
 Hemolytic crisis, with more pronounced jaundice due to accelerated
hemolysis.
 Aplastic crisis with dramatic fall in hemoglobin level and (reticulocyte count)-
decompensation
 megaloblastic changes
 Folate deficiency caused by increased bone marrow requirement.
 Pigment gall stone, in approximately half of untreated patients.
 Leg ulcer.

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 Abnormally low results of mean blood glucose via Glycated hemoglobin.
Treatment
 blood transfusions or exchanges
 Folic acid and splenectomy.
 Experimental gene therapy exists to treat hereditary spherocytosis in lab
mice
Prevalence
It is the most common disorder of the red cell membrane.