Summary about Disease
Hereditary spherocytosis (HS) is a genetic blood disorder characterized by abnormally shaped, spherical red blood cells (spherocytes). These spherocytes are more fragile than normal red blood cells and are prematurely destroyed in the spleen, leading to hemolytic anemia.
Symptoms
Anemia (fatigue, weakness, paleness)
Jaundice (yellowing of the skin and eyes)
Splenomegaly (enlarged spleen)
Gallstones (due to increased bilirubin production)
Dark urine
Causes
HS is caused by genetic mutations affecting proteins in the red blood cell membrane. These mutations disrupt the cell's structure, causing it to become spherical and less deformable. Common affected proteins include ankyrin, spectrin, band 3, and protein 4.2. The inheritance pattern is usually autosomal dominant, meaning one copy of the mutated gene is sufficient to cause the disorder. However, autosomal recessive and spontaneous mutations can also occur.
Medicine Used
Folic acid supplements: To support red blood cell production.
Iron supplements: If iron deficiency develops due to chronic hemolysis.
Vaccinations: To prevent infections, especially after splenectomy.
Blood transfusions: In severe cases of anemia.
Ursodeoxycholic acid: To help dissolve small gallstones, or prevent them.
Is Communicable
No, hereditary spherocytosis is not communicable. It is a genetic disorder and cannot be spread from person to person.
Precautions
Genetic counseling for individuals with a family history of HS.
Monitor for signs and symptoms of anemia, jaundice, and gallstones.
Avoid situations that may trigger hemolytic crises (e.g., infections).
Vaccinations to protect against infections, particularly after splenectomy.
Individuals considering splenectomy should carefully evaluate the risks and benefits with their healthcare provider.
How long does an outbreak last?
Hereditary spherocytosis is not an "outbreak" illness. It is a chronic, genetic condition. However, affected individuals may experience hemolytic crises which can last days to weeks, triggered by infections or other stressors.
How is it diagnosed?
Complete blood count (CBC): Shows anemia and increased mean corpuscular hemoglobin concentration (MCHC).
Peripheral blood smear: Reveals the presence of spherocytes.
Direct antiglobulin test (DAT or Coombs test): To rule out autoimmune hemolytic anemia (usually negative in HS).
Osmotic fragility test: Measures the red blood cells' ability to withstand hypotonic solutions (increased fragility in HS).
EMA (eosin-5-maleimide) binding test: Flow cytometry measures EMA binding to RBC membrane proteins. Reduced binding is seen in HS.
Genetic testing: To confirm the specific genetic mutation (not always necessary for diagnosis).
Timeline of Symptoms
HS symptoms vary widely. In some, symtoms are present from birth. In others, symptoms present in later childhood or even adulthood.
Infancy/Childhood: Jaundice, anemia, splenomegaly are common.
Adulthood: Gallstones, chronic anemia symptoms. Hemolytic crises can occur at any age, triggered by infection or other stressors.
Important Considerations
Splenectomy: Often considered in severe cases to reduce red blood cell destruction. However, it increases the risk of serious infections, especially with encapsulated bacteria. Vaccinations and prophylactic antibiotics are crucial after splenectomy.
Pregnancy: Women with HS should be closely monitored during pregnancy due to increased risk of complications.
Genetic counseling: Important for families with HS to understand the inheritance pattern and risk of recurrence.
Monitoring for complications: Lifelong monitoring for anemia, gallstones, and other complications is essential.
Severity Varies: The severity of HS can vary greatly among affected individuals, even within the same family.