Hereditary spherocytosis is characterised by ?
Hereditary spherocytosis is a genetic disorder affecting red blood cells. The main issue is the RBC membrane defect, specifically in proteins like ankyrin, spectrin, or band 3. This leads to the cells becoming spherical instead of biconcave, making them more prone to destruction in the spleen. The result is hemolytic anemia, jaundice, and splenomegaly.
The correct answer should mention the membrane defect and the resulting spherocytes. Let me check the options. The correct answer here wasn't provided, but according to standard questions, the correct option would likely be something like "Defect in RBC membrane proteins leading to spherocytes."
Now, the other options might include things like G6PD deficiency (which is a different enzyme issue), or maybe a metabolic defect. I need to make sure each wrong option is explained as incorrect. For example, G6PD deficiency causes hemolysis but through a different mechanism, not membrane defects.
The clinical pearl should highlight that hereditary spherocytosis is the most common inherited hemolytic anemia in Caucasians and that splenectomy is a treatment option. Also, remember that spherocytes are seen on peripheral smear, which is a key diagnostic feature.
Wait, the user's example had specific sections. Let me structure the explanation accordingly. Core concept first: membrane proteins defect leading to spherocytes. Then why correct is right, then each wrong option. Clinical pearl about the key features and diagnosis. Make sure to keep each section concise and within the character limit. Also, avoid markdown except for bold and bullets. Let me double-check the terminology and mechanisms to ensure accuracy.
**Core Concept**
Hereditary spherocytosis (HS) is an **autosomal dominant** disorder caused by **defects in red blood cell (RBC) membrane proteins** (e.g., ankyrin, spectrin, band 3). These defects destabilize the RBC membrane, leading to **spherocyte formation** and **splenic sequestration**, resulting in **chronic hemolytic anemia**.
**Why the Correct Answer is Right**
In HS, mutations in cytoskeletal proteins disrupt the RBC membrane skeleton, reducing its flexibility. This causes RBCs to become **sphere-shaped (spherocytes)** instead of biconcave discoid shape. Spherocytes are more fragile and rigid, leading to **splenic destruction** due to their inability to pass through splenic sinusoids. Key features include **jaundice**, **splenomegaly**, and **anemia**. Diagnosis is confirmed by **peripheral blood smear** showing spherocytes and **osmotic fragility testing**.
**Why Each Wrong Option is Incorrect**
**Option A:** "Deficiency of G6PD" is incorrect. G6PD deficiency causes **acute hemolysis** due to oxidative stress, not chronic hemolysis or spherocytes.
**Option B:** "Defect in hemoglobin synthesis" is incorrect. This describes **thalassemias**, not HS, which involves membrane defects.
**Option C:** "Increased