Thalassemias and Hemoglobinopathies Flashcards

1
Q

Which protein increases as a compensatory response to chronic anemia?

A. Hepcidin

B. 2,3 Diphosphoglycerate

C. Transferrin

D. Cubilin

A

B. 2,3 Diphosphoglycerate

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2
Q

Where is Vitamin B12 absorbed into blood?

A.Stomach

B. Duodenum

C. Jejunum

D. Terminal Ileum

A

D. Terminal Ileum

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3
Q

Contrast thalassemias and hemoglobinopathies

A

Thalassemias >> synthesis prob (deficient synthesis of globin chain)

Hemoglobinopathies >> structural prob (Hb chain structural abnormalities)

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4
Q

Contrast alpha thalassemia in AAs and in SE asians (what mutation does each population carry and are the patients symptomatic?

A

In African americans, a-thalassemia will manifest as a silent carrier scenario in which one copy is dysfunctional. The patients are usually asymptomatic

It can also manifest as thalassemia minor, in which a trans alpha deletion (2 copies from two separate chromosomes deleted; pt will have small RBcs but otherwise normal)

In SE asians, thalassemia minor is the same as that in AA’s except the deletiion is a cis-deletion

In SE asian children, a-thalassemia can present as thalassemia major (all the alpha copies are deleted) >> increased risk for hydrops fetalis >> death in utero

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5
Q

In alpha thalassemia major with hydrops fetalis, the children have Hb that has excess gamma chains, called ___, or Hb H that has excess ___

A

In alpha thalassemia major with hydrops fetalis, the children have Hb that has excess gamma chains, called Hb Barts, or Hb H that has excess beta chains

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6
Q

How does hemoglobin H disease arise? Pts with this disease have marked ___ and ___. Morphologically, the rbcs have ___ which are precipitates of ___

A

Hemoglobin H disease arises from 3 dysfunctional copies of alpha. Pts with this disease have marked anemia and microcytosis. Morphologically, the rbcs have Heinz bodies which are precipitates of beta globins

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7
Q

What are the various combinations of Beta thalassemia?

A
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8
Q

In beta thalassemia minor, you see basophilic stippling, which results from ___?

A

Excess alpha is precipitated coz ratio is skewed towards alpha – causes basophilic stippling >> leads to red cell killing in the spleen >> anemia

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9
Q

In what other conditions do you see basophilic stippling? (Baste the ox TAIL)

A

Thalassemia

ACD

iron deficiency

lead toxicity

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10
Q

In beta thalassemia intermedia and major, the RBCs exhibit ___ (varying size and shape of cells). Symptoms start to arise after ___ when fetal Hb levels start to fall

What are some complications that can arise from B-thalassemia?

A

In beta thalassemia intermedia and major, the RBCs exhibit anisopoikolocytosis (varying size and shape of cells). Symptoms start to arise after 6 months when fetal Hb levels start to fall

Ineffective erythropoiesis

Iron overload

Extravscular hemolysis

Skeletal deformities

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11
Q

Which lab finding would you expect in a patient with beta-thalassemia?

A.Increased RBC count

B. Low MCV

C. Decreased Hb A2

D. A&B

E. A,B,C

A

Both A and B

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12
Q

Sickle cell anemia arises from a __ to __ mutation (adenine to thymine substitution)

How do the sickle cells form?

What are the 3 drivers of sickling?

A

Sickle cell anemia arises from a Glu to Val mutation (adenine to thymine substitution)

Deoxyhemoglobin S forms fibers that become very rigid and are held together by the valine that’s not supposed to be there

Low pH>>O2 tension

Intracellular dehydration

Decreased transit times thru vascular beds

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13
Q

Sickle cell anemia can lead to ___ anemia (specifically __ hemolysis). Infection with ___ can also cause aplastic crisis. Because the spleen eventually involutes due to trapping of RBCs, patients become more susceptible to bacterial infections, namely ___ and ___

A

Sickle cell anemia can lead to hemolytic anemia (specifically intravascular hemolysis). Infection with parvovirus can also cause aplastic crisis. Because the spleen eventually involutes due to trapping of RBCs, patients become more susceptible to bacterial infections, namely Pneumoccocal and Salmonella infections (also Neisseria)

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14
Q

Sickle cell anemia patients can also get ___, which is the most common cause of death, as well brain infarctions that can lead to stroke

A

Sickle cell anemia patients can also get pulmonary infarctions, which is the most common cause of death, as well brain infarctions that can lead to stroke

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15
Q

How would you treat sickle cell anemia? (state 5 things)

A

RBC exchange

Stem cell transplant

Give vacccines for Pneumoccoci and Neisseria

Keep hydrated

Give hydroxyurea (increases HbF and reduces frequency of painful episodes)

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16
Q

Sickle cell trait causes ___ and ___, and is denoted by __ and __ bands on a gel

A

Sickle cell trait causes hemoturia and splenic infarction, and is denoted by S and A bands on a gel

17
Q

How is increased HbF protective in sickle cell patients?

A.Since there is no beta globin, cells don’t sickle as readily

B. HbF binds O2 with greater affinity thus increasing O2 delivery

C. HbF inhibits HbSS polymerization

D. A&B

E. A,B,C

A

A,B,C

18
Q

Hemoglobin C disease is characterized by a glu to __ mutation and __- cells on a peripheral blood smear

A

Hemoglobin C disease (milder than HbSS) is characterized by a glu to lys mutation and target cells on a peripheral blood smear

19
Q

Under which circumstances would you see target cells? (HALT says the hunter to his target)

A

Hb C

Asplenia

Liver disease

Thalassemia