Spherocytosis
last authored: Oct 2009, Dave LaPierre
last reviewed:
Introduction
Spherocytosis is a hemolytic anemia caused by mutations in red blood cell membrane protein. It has a varying clinical picture, from mild anemia to severe, life-threatening disease.
It is the most common hemolytic anemia.
The Case of...
a simple case introducing clincial presentation and calling for a differential diagnosis. To get students thinking.
Causes and Risk Factors
Over 3/4 of cases show autosomal dominant inheritance. The other 25% suggest spontaneous mutation.
Pathophysiology
Abnormalities in membrane proteins ankyrin or spectrin causes RBCs to form spheres. These spherocytes are less flexible and are destroyed in the microvasculature. They are also removed from the circulation by reticuloendothelial cells in the spleen.
Compensation is straightforward in mild cases. However, infection can lead to exacerbations.
Signs and Symptoms
Signs and symptoms of anemia may be present.
Severe disease can lead to splenomegaly.
Investigations
- lab investigations
- diagnostic imaging
Lab Investigations
Blood smear shows spherocytes.
The osmotic fragility test may also be helpful.
Diagnostic Imaging
Treatments
Transfusions and splenectomy may be required.
Supplementation with folate and B12 may be helpful.
Genetic counselling is helpful, given the inheritance of most cases.
Consequences and Course
As described, most cases are mild. However, severe disease can lead to splenomegaly, growth failure, gallstones, neonatal jaundice, and chronic transfusion.
Resources and References
Topic Development
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