Thalassemia

Question 1

what is thalassemia?

Answer 1

hypochromic, microcytic, and is a result of a defect in either the alpha or beta globin chains

Question 2

what causes the defect in an alpha or beta chain in thalassemia?

Answer 2

when genes related to the globin protein are missing or changed

Question 3

what is the hallmark of thalassemia?

Answer 3

an imbalance globin chain synthesis

Question 4

this is the most common single-gene disorder in the world

Answer 4

thalassemia

Question 5

is thalassemia inherited or spontaneous?

Answer 5

inherited

Question 6

this type of thalassemia is associated with chromosome 11

Answer 6

Beta-thalassemia

Question 7

this type of thalassemia is associated with chromosome 16

Answer 7

Alpha-thalassemia

Question 8

what is the coloration and size associated with thalassemia?

Answer 8

hypochromic and microcytic

Question 9

what are the most common causes of Beta-thalassemia?

Answer 9

deranged splicing of the mRNA precursor or premature termination of mRNA translation

Question 10

what causes chipmunk facies and frontal bossing?

Answer 10

extramedullary erythropoiesis since RBCs can no longer be made in bone marrow or traditional locations

Question 11

ineffective erythropoiesis can lead to excessive absorption of what?

Answer 11

iron

Question 12

in thalassemia, is hepcidin suppressed or encouraged?

Answer 12

suppressed

Question 13

what organ can be damaged in thalassemia?

Answer 13

liver

Question 14

what is the Hb level associated with Beta-thalassemia major (homozygous)?

Answer 14

Hb

Question 15

what is the Hb level associated with Beta-thalassemia intermedia?

Answer 15

Hb level 7-10

Question 16

what are some common manifestations seen with Beta-thalassemia major (Cooley’s anemia)?

Answer 16

• fatigue
• jaundice
• hepatosplenomegaly
• dark urine
• bone deformities
• leg ulcers
• cholelithiasis
• stunted growth
• delayed puberty
• cachexia

Question 17

what is the most severe form of Alpha-thalassemia?

Answer 17

Hydrops fatalis; child dies in utero or shortly after birth

Question 18

is thalassemia micro, macro, or normocytic?

Answer 18

microcytic

Question 19

what might you see on a blood smear of thalassemia?

Answer 19

• microcytosis
• hypochromia
• anisopoikilocytosis
• nucleated RBCs
• target cells

Question 20

why would you do a hemoglobin test if you suspect your patient has thalassemia?

Answer 20

to differentiate what type of Hb chains they have in order to determine their type of thalassemia

Question 21

what index is used to determine if your patient has thalassemia or iron deficiency?

Answer 21

Mentzer index (MCV/RBC count)
> 13 = iron deficiency

Question 22

what serum level can be used to differentiate between iron deficiency and thalassemia?

Answer 22

ferritin; will be low if iron deficient but normal in thalassemia

Question 23

how does the MCV differ between Alpha-thalassemia and HbH disease?

Answer 23

Alpha-thalassemia has MCV 65-75 fL

HbH disease has MCV 55-65 fL

Question 24

how do you treat heterozygotes of thalassemia (carries)?

Answer 24

no treatment really aside form genetic counseling

Question 25

what is the conventional treatment of thalassemia major and thalassemia intermedia?

Answer 25

regular blood transfusion and iron chelation

Question 26

which thalassemia may require a splenectomy?

Answer 26

thalassemia major