All of the following are true of β thalassemia major, except –
**Core Concept**
β thalassemia major, also known as Cooley's anemia, is a severe form of **thalassemia** that affects the production of the **beta-globin** chains of **hemoglobin**. This genetic disorder leads to severe **anemia**, requiring regular **blood transfusions**. The underlying defect involves mutations in the **HBB gene**.
**Why the Correct Answer is Right**
Since the correct answer options are not provided, let's discuss the general characteristics of β thalassemia major. It is characterized by a marked reduction in the production of **beta-globin** chains, leading to a severe imbalance in the **alpha-globin** to **beta-globin** chain ratio. This imbalance causes **ineffective erythropoiesis** and **hemolysis**, resulting in severe **anemia**.
**Why Each Wrong Option is Incorrect**
**Option A:** Without the specific option details, we can't directly address why each option is incorrect. However, commonly incorrect statements about β thalassemia major might include misconceptions about its inheritance pattern, clinical presentation, or management strategies.
**Option B:** Similarly, without specifics, we can say that incorrect options might relate to the pathophysiology, such as misunderstanding the role of **iron overload** or the importance of **chelation therapy**.
**Option C:** Incorrect options might also involve confusion about the distinction between **β thalassemia major** and **β thalassemia minor**, or the role of **gene therapy** in treatment.
**Option D:** Another area of confusion could be the clinical manifestations, such as **growth retardation**, **bone deformities**, or **cardiac complications**.
**Clinical Pearl / High-Yield Fact**
A key point to remember is that **β thalassemia major** requires lifelong management, including regular **blood transfusions** and **iron chelation therapy** to prevent **iron overload**, which can lead to **cardiac** and **hepatic** complications.
**Correct Answer:** Correct Answer: D. Increased production of beta chains.