Thalassemia

Question 1

A child is diagnosed with antenatal hydrops and thalassemia. What category of thalassemia must they have? (alpha or beta)

Answer 1

Alpha thalassemia

can’t make adequate HbF = A2G2

Question 2

HbA

Answer 2

A2Beta2

Question 3

HbA2

Answer 3

A2Delta2

Question 4

HbF

Answer 4

A2Gamma2

Question 5

When do babies with beta thalassemia become symptomatic?

Answer 5

6-12 months of life (after HbF drops)

Question 6

Clinical features of severe thalassemia

Answer 6

Thalassemia facies (maxilla hypoplasia, frontal bossing, flat nasal bridge)
Pathologic fractures
Hepatosplenomegaly
Cachexia
Poor growth

Question 7

Side effects of iron chelators

Answer 7

hearing loss
peripheral neuropathy
poor growth

Question 8

Two major systems affected by iron overload

Answer 8

Endo (hypopituitarism)

Cardiac (CHF, arrhythmias)

Question 9

clinical phenotype of

–A/AA

Answer 9

clinically silent!

Question 10

What is this called, and what population is it most common in?

–A/–A

Answer 10

Trans alpha thalassemia trait

most common in people of african descent

Question 11

What is this called, and what population is it most common in?

—-/AA

Answer 11

Cis alpha thalassemia trait deletion

most common in Asian or Mediterranean populations

Question 12

– – / – A

What does this result in?

Answer 12

Alpha thalassemia 3 gene deletion causes formation of Hb Barts (gamma globin tetramers) and Hb H (beta globin tetramers) resulting in hemolysis and severe microcytosis

Question 13

Ways to treat HbH alpha-thal?

Answer 13

Folate supplementation

Splenectomy may decrease hemolysis (improve Hgb)

If < 15 yrs old and have matched sib donor, consider HSCT

Question 14

Alpha globin gene:
– –/– –

What does this result in?

Answer 14

No normal hemoglobins are produced - causes severe fetal anemia, hydrops. Usually fatal