Fatal hemoglobin has all the following characteristic features except
**Core Concept**
Fatal hemoglobin has a unique set of characteristics that distinguish it from other hemoglobinopathies. It is a rare genetic disorder characterized by a mutation in the beta-globin gene, leading to the production of abnormal hemoglobin that can cause severe anemia and other complications.
**Why the Correct Answer is Right**
Fatal hemoglobin, also known as beta-zero thalassemia or Hb Bart's hydrops fetalis syndrome, is a severe form of thalassemia that is incompatible with life. The abnormal hemoglobin produced in this condition has a significantly reduced ability to bind oxygen, leading to severe anemia and tissue hypoxia. The condition is usually diagnosed prenatally or in early infancy and is often fatal if not treated promptly.
**Why Each Wrong Option is Incorrect**
* **Option A:** This option is incorrect because fatal hemoglobin is indeed characterized by a marked elevation in fetal hemoglobin levels. The high levels of fetal hemoglobin can lead to a range of complications, including severe anemia and heart failure.
* **Option B:** This option is incorrect because the beta-zero thalassemia mutation leads to a complete absence of beta-globin chains, which results in the production of abnormal hemoglobin. The mutation does not lead to an increase in alpha-globin chains.
* **Option C:** This option is incorrect because the condition is indeed characterized by a marked increase in red blood cell destruction, leading to severe anemia and other complications.
**Clinical Pearl / High-Yield Fact**
Fatal hemoglobin is a rare but severe form of thalassemia that highlights the importance of prenatal diagnosis and early intervention in managing genetic disorders.
**Correct Answer: D.**