Understanding Hemoglobin and Related Disorders

These flashcards cover key concepts related to hemoglobin, its synthesis, function, various disorders, and diagnostic approaches.

What is the molecular structure of adult hemoglobin?

Adult hemoglobin consists of two alpha (α) and two beta (β) globin chains, represented as α2β2.

What is the primary function of hemoglobin?

The primary function of hemoglobin is to carry oxygen and deliver it to tissues.

What is the heme group in hemoglobin composed of?

The heme group consists of a protoporphyrin ring with a central iron atom.

What is the typical P50 value of hemoglobin at 37ºC and pH 7.4?

The P50 value is normally 27 mmHg.

Which two families of globin genes exist?

The two families of globin genes are alpha (α) and non-alpha (non-α).

What are the three distinct embryonic hemoglobins synthesized during early development?

The three distinct embryonic hemoglobins are Hb Gower I (ζ2ε2), Hb Portland (ζ2γ2), and Hb Gower II (α2ε2).

What does thalassemia refer to?

Thalassemia refers to a reduced rate of production of one or more globin chains.

What is the normal range of RBC for an adult female?

3.8-5.8 x 10^12/L.

What are common symptoms associated with beta thalassemia major?

Intense chronic hemolytic anemia, dependency on transfusion, and potential for skeletal deformities.

What is the significance of a left-shifted oxygen dissociation curve?

A left-shifted curve indicates increased affinity of hemoglobin for oxygen.

What is the abnormality in sickle cell disease?

Sickle cell disease is caused by the mutation of the sixth amino acid of beta globin from glutamic acid to valine.

What characterizes the Hb H disease?

Hb H disease is characterized by a single active alpha gene and can lead to mild to moderately severe hemolytic anemia.

Which condition is incompatible with extrauterine life due to absence of alpha genes?

Absence of all four copies of the alpha gene (alpha thalassemia major) is incompatible with life.

What are the two types of globin gene clusters?

Alpha globin gene clusters are located on chromosome 16, while beta globin gene clusters are on chromosome 11.

What does HPLC stand for, and what is its purpose?

HPLC stands for High-Pressure Liquid Chromatography, used to separate, identify, and quantify components in a mixture.

What is the main difference between alpha and beta thalassemias?

Alpha thalassemias are associated with genetic deletions affecting α-globin genes, while beta thalassemias involve mutations in β-globin genes.

What happens to the affinity of hemoglobin when one heme takes on oxygen?

The affinity of the remaining hemes of the tetramer increases markedly.

What are the blood features associated with microcytic hypochromic anemia?

Features include reduced MCV, hypochromia, and may include target cells.

What role does protoporphyrin play in heme synthesis?

Protoporphyrin is a critical component in the formation of the heme group.

How does iron overload occur in patients with beta thalassemia major?

Iron overload occurs due to excessive intestinal absorption and frequent blood transfusions.

What does a reticulocyte count indicate?

A reticulocyte count can indicate the bone marrow's response to anemia or blood loss.

What is the structure of HbA2?

HbA2 is formed by two alpha (α) and two delta (δ) globin chains (α2δ2).

What is the expected percentage of fetal hemoglobin (HbF) in newborns?

Fetal hemoglobin (HbF) is expected to be around 80% in newborns.

What are Hb crystal formations indicative of?

Hb crystal formations can indicate specific structural changes in hemoglobin.

What is hereditary persistence of fetal hemoglobin?

It is a benign condition where fetal hemoglobin production continues into adulthood.

What are the normal adult hemoglobin values for males?

The normal adult hemoglobin values for males range from 130-180 g/L.

What does the term 'hemolysis' refer to in thalassemia?

Hemolysis refers to the breakdown of red blood cells, which is exaggerated in thalassemia.