HEREDITARY SPHEROCYTOSIS - PATHOLOGY

Summary

The video script delves into the hereditary spherocytosis disorder, discussing its pathology, including the mutation in the spectrin protein causing red blood cell deformities. It highlights the clinical findings such as jaundice, splenomegaly, and the formation of gallstones. The script emphasizes the importance of understanding the structural defects in red blood cells due to spectrin mutations, which lead to reduced life span and the development of anemia and reticulocytosis. It also touches on the treatment options, particularly the benefits of splenectomy for patients with hereditary spherocytosis.

Takeaways

• 🧬 Hereditary spherocytosis is an autosomal dominant disorder characterized by a reduced life span of red blood cells.
• 🩸 The normal life span of red blood cells is 120 days, but in hereditary spherocytosis, it is reduced to 10 to 20 days.
• 🔬 The condition involves mutations in the spectrin protein, which is part of the red blood cell membrane and contributes to its stability.
• 🔑 The most common mutation is seen in the protein 4.2, which is crucial for maintaining the integrity of the red blood cell membrane.
• 📚 Spectrin has alpha and beta subunits that attach to the cell membrane at different sites, and mutations can affect these attachment sites.
• 🔍 The diagnosis of hereditary spherocytosis often involves identifying the structural defect in the red blood cell membrane due to mutations in spectrin.
• 🌡 The condition can lead to extravascular hemolysis, where red blood cells are destroyed outside the blood vessels, causing anemia.
• 💉 Splenectomy is a common treatment for hereditary spherocytosis, as it can help reduce the destruction of red blood cells.
• 🩹 After splenectomy, the anemia is corrected, but the spherocytes, which are abnormally shaped red blood cells, will remain in the blood.
• 🧫 The osmotic fragility test is a key diagnostic tool, where red blood cells from patients with hereditary spherocytosis are more prone to rupture.
• 🛡 Vaccination against encapsulated organisms such as pneumococcus, Haemophilus influenzae, and meningococcus is important after splenectomy to prevent infections.

Q & A

What is Hereditary Spherocytosis?

Hereditary Spherocytosis is an autosomal dominant disorder characterized by the presence of abnormally shaped red blood cells, or spherocytes, which can lead to hemolysis and anemia.

What is the normal life span of red blood cells in Hereditary Spherocytosis?

In Hereditary Spherocytosis, the life span of red blood cells is significantly reduced, typically to 10 to 20 days, compared to the normal life span of 120 days.

What is the role of Spectrin in red blood cells?

Spectrin is a protein that forms a part of the red blood cell membrane skeleton. It helps maintain the cell's shape and flexibility, and mutations in the Spectrin gene can lead to Hereditary Spherocytosis.

How do mutations in the Ankyrin protein affect Hereditary Spherocytosis?

Ankyrin mutations can result in the disruption of the binding of Spectrin to the red blood cell membrane, leading to a loss of membrane stability and the formation of spherocytes.

What is the clinical significance of Band 3 in the red blood cell membrane?

Band 3 is a crucial protein that facilitates the transport of anions across the red blood cell membrane. Mutations in Band 3 can contribute to the development of Hereditary Spherocytosis.

What are the clinical findings associated with Hereditary Spherocytosis?

Clinical findings in Hereditary Spherocytosis include jaundice, splenomegaly, and the formation of gallstones, which are due to the increased breakdown of red blood cells and bilirubin production.

Why is splenomegaly common in Hereditary Spherocytosis?

Splenomegaly occurs because the spleen filters out the abnormal spherocytes from the bloodstream, leading to an enlarged spleen as it works to remove these cells.

What is the typical treatment for Hereditary Spherocytosis?

The most common treatment for Hereditary Spherocytosis is splenectomy, which is the surgical removal of the spleen to reduce the destruction of red blood cells.

What are the consequences of not treating Hereditary Spherocytosis?

If left untreated, Hereditary Spherocytosis can lead to chronic anemia, fatigue, and complications such as gallstones and an increased risk of infections due to a weakened immune system.

How does the loss of potassium and water affect the red blood cells in Hereditary Spherocytosis?

The loss of potassium and water can cause the red blood cells to become more rigid and less able to deform, which is crucial for their passage through the spleen and other narrow vessels.

What is the role of the sodium-potassium pump in red blood cells?

The sodium-potassium pump is essential for maintaining the proper balance of ions inside and outside the red blood cells, which is critical for their function and shape.