Thalassemia Flashcards
A child is diagnosed with antenatal hydrops and thalassemia. What category of thalassemia must they have? (alpha or beta)
Alpha thalassemia
can’t make adequate HbF = A2G2
HbA
A2Beta2
HbA2
A2Delta2
HbF
A2Gamma2
When do babies with beta thalassemia become symptomatic?
6-12 months of life (after HbF drops)
Clinical features of severe thalassemia
Thalassemia facies (maxilla hypoplasia, frontal bossing, flat nasal bridge) Pathologic fractures Hepatosplenomegaly Cachexia Poor growth
Side effects of iron chelators
hearing loss
peripheral neuropathy
poor growth
Two major systems affected by iron overload
Endo (hypopituitarism)
Cardiac (CHF, arrhythmias)
clinical phenotype of
–A/AA
clinically silent!
What is this called, and what population is it most common in?
–A/–A
Trans alpha thalassemia trait
most common in people of african descent
What is this called, and what population is it most common in?
—-/AA
Cis alpha thalassemia trait deletion
most common in Asian or Mediterranean populations
– – / – A
What does this result in?
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
Ways to treat HbH alpha-thal?
Folate supplementation
Splenectomy may decrease hemolysis (improve Hgb)
If < 15 yrs old and have matched sib donor, consider HSCT
Alpha globin gene:
– –/– –
What does this result in?
No normal hemoglobins are produced - causes severe fetal anemia, hydrops. Usually fatal