Thalassemia Flashcards
What causes thalassemias?
Decreased production of alpha or B chain->imbalance of a and B-> ineffective erythropoiesis
Which type of thalassemia is more associated with a point mutations in the DNA?
Beta=point mutations + deletions
α= deletion
What are the clinical manifestations of Thalassemia?
- Small RBC (dec MCV)
- Low MCHC (mean heme concenctration)
- Inc RBC production
- Splenomegaly
What is HB H disease?
It is a –/-+ genotype of alpha thalassemia
AKA Thalassemia intermedia
Which population has greater +- genotype for alpha trait?
African
Asians have ++/–
How is Alpha Thalassemia diagnosed?
2 gene deletion= microcytosis
3 gene= anemia + microcytosis
Make sure there are no Iron def and normal electrophoresis.
What is the name of the disease associated with B0/B0 thalassemia? What are the characteristics?
Cooley’s Anemia or Beta Major
- Dense skull, “hair on end”
- Splenomegaly
How do you distinguish between a and B thalassemia?
With a Electophoresis after lab tests.
Alpha will have normal EP.
Which type of B Thalassemia is ALWAYS transfusion dependent?
Cooley’s (B major)
HbE-B0 is often dependent.
What causes Hb E?
β26(glu→lys)
How do you distinguish between iron def, alpha trait, and beta trait?
Iron Def- look for dec RBC count
Alpha- Inc RBC and normal Electrophoresis.
B Trait- abnormal Electrophoresis
Why is hydroxyurea used to treat thalasemias?
It increases fetal Hemoglobin production in patients with B thal.
When does hemoglobin barts show up?
in –/-+ or –/– alpha thal traits.
What is Hb A2 made of?
delta 2 alpha 2
What is chelation used for?
Iron overload
