Thalassemia

Question 1

at what level of MCV should you think about thalassemia major

Answer 1

70

Question 2

Hemoglobin S, beta-thalassemia electrophoresis

Answer 2

hemoglobin s + hemoglobin A (with major there is severely decreased beta-globin production)

Question 3

Hemoglobin E pathophys

Answer 3

Point mutation in the Beta-globin gene that causes decreased production of beta-globin and results in a thalassemia-like syndrome

Question 4

Hemoglobin E clinical features

Answer 4

mild anemia + mild splenomegaly + no acute pain events

Question 5

Alpha-thalassemia trait lab features

Answer 5

chronic mild microcytic anemia (Hgb around 10)

Question 6

Alpha-thalassemia trait electrophoresis

Answer 6

Normal electrophoresis pattern (decreased hemoglobin A levels, but migrate in a normal pattern on electrophoresis)

Question 7

Beta-thalassemia minor clinical features

Answer 7

chronic microcytic anemia

Question 8

Beta-thalassemia minor electrophoresis pattern

Answer 8

• Increased amounts of hemoglobin A2 (excess alpha chains link with other chains to produce increased amounts)
• no HbA1

Question 9

electrophoresis pattern in beta thalassemia major

Answer 9

• increased HbA2 (body compensates by producing more HbA2 which is composed of delta subunits not beta)
• reduced HbA
• increased HbF

Question 10

what is the normal hemoglobin protein structure

Answer 10

HbA (adult hemoglobin), which has 2 alpha and 2 beta subunits

Question 11

what is hemoglobin A2?

Answer 11

Normal variant of hemoglobin A, consisting of 2 alpha and 2 delta chains, which is found at low levels in normal human blood

Question 12

Nomenclature for beta thalassemia major

Answer 12

B0/B0

Question 13

Nomenclature for beta thalassemia intermedia

Answer 13

B+/B0

Question 14

Nomenclature for beta thalassemia minor

Answer 14

B+/B+

Question 15

HbE/Beta thalassemia clinical features

Answer 15

• Asian people

Question 16

Hemoglobin E disease – homozygotes clinical features

Answer 16

• minimal anemia

- target cells

Question 17

HbS- alpha thalassemia clinical features

Answer 17

• less severe than sickle cell-beta thalassemia (alpha thalassemia leads to beta globin production, which are less toxic to RBC membrane than alpha globin chairs)

Question 18

Unique features of hemoglobin SC disease

Answer 18

• milder clinical course than sickle cell BUT all the same complications has hemoglobin SS
• more significant retinopathy, cerebral fate embolism, and ischemic necrosis of bone and priapism (HbC leads to dehydration of the SC red cell, leading to serious clinical sequelae)

Question 19

Hemoglobin C disease clinical features

Answer 19

• moderate *normocytic anemia
• component of hemolytic anemia
• splenomegaly

Question 20

Sickle cell variant that has similar phenotype to sickle cell disease

Answer 20

• hgbS-beta thalassemia (they have similar acute pain episode frequency and are at similar risk of ACS)

Question 21

Pathophys of hemoglobin C disease

Answer 21

point mutation in beta globin chain (substitution of glutamic acid for lysine)

Question 22

End organ liver damage more common in thalassemia than in SCD

Answer 22

Endocrinopathy and cardiomyopathy (sickle cell patients tend to just develop liver iron loading)

Question 23

Prevention of neonatal hemochromatosis

Answer 23

Weekly IVIG