Deck 11: Hemolytic Anemias: Intracorpuscular Defects: III the Hemoglobinopathies

Question 1

Hemoglobin is a conjugated protein with a molecular weight of approximately 68,000. It is composed of which of the following?

A) Iron
B) Protoporphyrin IX type III
C) Globin
D) All of the above

Answer 1

All of the above

Question 2

Which of the following represents quantitative hemoglobinopathies characterized by a decreased production of hemoglobin with a decreased synthesis of one particular globin chain?

A) Sickle cell anemia
B) Hemoglobin C disease
C) Thalassemia
D) All of the above
E) None of the above

Answer 2

Thalassemia

Question 3

What is the most common pattern of inheritance for hemoglobinopathies?

A) Autosomal dominant
B) Autosomal recessive
C) Codominant
D) X-linked
E) Any of the above

Answer 3

Codominant

Question 4

Which of the following can precipitate or promote sickling of red blood cells?

A) Decrease in oxygenation
B) Decrease in pH
C) Dehydration
D) All of the above
E) None of the above

Question 5

Which of the following represents a type of sickle cell crisis?

A) Hemolytic
B) Aplastic
C) Painful (vaso-occlusive)
D) All of the above
E) None of the above

Question 6

Which of the following represents major categories of hemoglobinopathies?

A) Aggregating hemoglobins
B) Unbalanced synthesis of hemoglobin
C) Unstable hemoglobin
D) Hemoglobins with abnormal heme function
E) All of the above

Question 7

The gene for hemoglobin S occurs with greatest frequency in which country?

A) United States
B) Europe
C) Central Africa
D) Asia
E) Australia

Question 8

At the molecular level, which is the most common cause of a hemoglobinopathy?

A) A single-base DNA substitution in the corresponding triplet codon
B) Multiple-base substitutions in the triplet codon
C) The production of long or short subunits
D) The occurrence of fusion subunits
E) All of the above

Question 9

Which of the following represents globin chains that may combine with alpha chains to form a particular hemoglobin?

A) Beta ()
B) Gamma ()
C) Delta ()
D) Epsilon ()
E) All of the following

Question 10

Which of the following represents embryonic hemoglobins formed only in the embryonic stages of human development?

A) (₂₂)
B) (₂₂)
C) (₂₂)
D) All of the above
E) None of the above

Question 11

The sickling process in sickle cell anemia can lead to which of the following clinical manifestations?

A) Hypoxia
B) Painful crises
C) Infarction
D) Severe chronic hemolytic anemia
E) All of the above

Question 12

Sickle cell anemia represents the homozygous form of the disease in which the individual inherits how many abnormal genes that code for hemoglobin S?

A) 1
B) 2
C) 3
D) 4
E) Any of the above

Question 13

What percentage of hemoglobin variants represents single amino acid substitutions in the globin chains?

A) 90%
B) 10%
C) 50%
D) 20%

Question 14

Which of the following classic hematologic features of sickle cell anemia can be observed on the peripheral blood smear?

A) Target cells
B) Nucleated red cells
C) Sickle cells
D) Anisocytosis and poikilocytosis
E) All of the above

Question 15

The majority of hemoglobinopathies result from abnormalities in what chain?

A) Alpha
B) Beta
C) Gamma
D) Delta
E) Epsilon

Question 16

Which of the following clinical features is characteristic of sickle cell anemia?

A) Severe anemia
B) Cardiac enlargement (cardiomegaly)
C) Icterus
D) Leukocytosis
E) All of the above

Question 17

Which percentage of American blacks carry the trait (one gene) for hemoglobin S?

A) 0.16%
B) 8-10%
C) 20%
D) 40%
E) 50%

Question 18

The anemias of the hemoglobinopathies such as sickle cell are morphologically classified as:

A) Microcytic hypochromic
B) Normocytic normochromic
C) Macrocytic
D) Microcytic normochromic
E) Any of the above

Question 19

Which of the following amino acid substitution occurs in hemoglobin S?

A) Valine for glutamic acid
B) Glutamic acid for valine
C) Lysine for glutamic acid
D) Glutamic acid for lysine
E) None of the above

Question 20

Increases in which of the following hemoglobins can occur in adult patients with sickle cell anemia, thereby improving the anemia by modifying the degree and severity of the sickling?

A) HbA₂
B) Hb Gower
C) Hb Portland
D) HbF
E) HbH

Question 21

Which of the following rare hemoglobins also sickles, giving a positive tube solubility test?

A) HbC Georgetown
B) HbS Memphis
C) Hb Porto-Alegre
D) All of the above
E) None of the above

Question 22

Which of the following therapies represents the "mainstay" of treatment for painful crises to correct fluid and electrolyte deficits in patients with sickle cell anemia?

A) Aspirin
B) Hydration (administration of fluid volume)
C) Antibiotics
D) Transfusion therapy
E) Plasmapheresis

Question 23

Which of the following is characteristic of the vaso-occlusive or painful crisis in a patient with sickle cell anemia?

A) Severe pain
B) Tissue damage and necrosis
C) Regional hypoxia and acidosis
D) Dehydration or exposure to extreme cold
E) All of the above

Question 24

Which of the following laboratory findings may be characteristic of sickle cell anemia?

A) An average reticulocyte count between 5% and 20%
B) Neutrophilic leukocytosis with a shift to the left
C) Thrombocytosis
D) Marked erythroid hyperplasia
E) All of the above

Question 25

Which process listed below is commonly responsible for the symptoms of the hand-foot syndrome observed in sickle cell anemia?

A) Infarction
B) Infection
C) Bone marrow hyperplasia
D) Autosplenectomy
E) Ulceration

Question 26

What common renal complication is associated with sickle cell anemia?

A) Renal papillary necrosis
B) Glomerular nephritis
C) Dactylitis
D) Pyelonephritis
E) A and D

Question 27

Which of the following is characteristic of a hemolytic crisis in a sickle cell anemia patient?

A) Decrease in hemoglobin
B) Decrease in hematocrit
C) Increase in reticulocyte count
D) Jaundice
E) All of the above

Question 28

The most significant cause of death during early childhood is the severe overwhelming septicemia and meningitis due to what organism?

A) Rubeola
B) Streptococcus pneumoniae
C) Cytomegalovirus
D) Histoplasma capsulatum
E) Staphylococcus aureus

Question 29

Which of the following is characteristic of infections in patients with sickle cell anemia in comparison to healthy individuals?

A) Disseminate more rapidly
B) Difficult to resolve
C) Associated with a greater morbidity
D) All of the above
E) None of the above

Question 30

Although sickle cell trait is usually asymptomatic, sickling can still occur when caused by which of the following?

A) Severe respiratory infection
B) Air travel in unpressurized aircraft
C) Anesthesia
D) Congestive heart failure
E) All of the above

Question 31

Sickle cell trait represents what inherited form of the disease?

A) Heterozygous
B) Homozygous
C) X-linked
D) Any of the above
E) None of the above

Question 32

Multiple infarctions and subsequent fibrosis of the spleen lead to what process in adult patients with sickle cell anemia?

A) Splenomegaly
B) Hepatosplenomegaly
C) Autosplenectomy
D) Extramedullary hematopoiesis
E) All of the above

Question 33

Which of the following is characteristic of an "aplastic" type of sickle cell crisis?

A) Temporary bone marrow aplasia
B) Usually associated with infections
C) Associated with a low reticulocytic count
D) All of the above
E) None of the above

Question 34

What hemoglobin(s) is/are present in sickle cell trait?

A) HbA₂
B) HbS
C) HbA
D) A and B
E) B and C

Question 35

Which of the following sickle cell crises is the hallmark of sickle cell anemia?

A) Hemolytic
B) Aplastic
C) Painful or vaso-occlusive
D) Any of the above
E) None of the above

Question 36

Which of the following red cell inclusions may be seen in the RBCs of patients with sickle cell anemia as a result of rapid RBC turnover and "stressed" erythropoiesis?

A) Siderotic granules
B) Cabot rings
C) Howell-Jolly bodies
D) A and B
E) A and C

Question 37

Which of the following represents clinical manifestations of sickle cell anemia?

A) Leg ulcers
B) Cardiomegaly
C) Joint and skeletal problems
D) Infarcts that can occur anywhere in the bone
E) All of the above

Question 38

Which of the following describes dactylitis, which commonly occurs in infants and young children with sickle cell anemia?

A) Microinfarction of small bones
B) Unequal bone growth
C) Painful swelling of the hands and feet
D) Any of the above
E) None of the above

Question 39

Which of the following represents the standard principles of therapy in the management of painful crisis in a patient with sickle cell anemia?

A) Adequate rehydration
B) Sufficient analgesics to relieve pain
C) Antibiotic therapy
D) All of the above
E) None of the above

Question 40

Which of the following remains the major cause of morbidity and mortality in patients with sickle cell anemia?

A) Serious bacterial infections
B) Renal papillary necrosis
C) Bone marrow aplasia
D) Infarctions
E) Cardiomegaly

Question 41

Which of the following may be found on the hemoglobin electrophoretic pattern for sickle cell anemia?

A) No HbA (0%)
B) 80-100% HbS
C) 1-20% HbF
D) 2-4% HbA₂
E) All of the above

Question 42

Which of the following is characteristic of the peripheral blood smear in hemoglobin SC disease?

A) Target cells
B) Folded red cells
C) Occasional glove-shaped intracellular
D) Normocytic normochromic anemia
E) All of the above

Question 43

Which of the following is characteristic of HbC disease?

A) Mild chronic hemolytic anemia
B) Splenomegaly
C) Normocytic, normochromic anemia with numerous target cells (50-90%) and occasional folded cells
D) Hemoglobin C ("bar of gold") crystals present on peripheral smear of splenectomized patients
E) All of the above

Question 44

In hemoglobin SC disease what is the percentage of HbS and HbC found on the hemoglobin electrophoresis at alkaline pH?

A) 60:40
B) 40:60
C) 50:50
D) 20:80
E) 80:20

Question 45

Which of the following is characteristic of the hemoglobin electrophoresis at alkaline pH for hemoglobin SC disease?

A) 50% HbS
B) 50% HbC
C) <2% HbF
D) All of the above
E) None of the above

Question 46

Which of the following hemoglobin(s) is/are present in hemoglobin SC disease?

A) HbS
B) HbA
C) HbC
D) A and C
E) All of the above

Question 47

Which of the following abnormal hemoglobins will have a positive tube solubility test?

A) HbS
B) HbD
C) HbG
D) All of the above
E) None of the above

Question 48

Which of the following cannot be used as a screening test for hemoglobin S in newborns?

A) Tube solubility tests
B) Sodium metabisulfite sickle prep
C) Hemoglobin electrophoresis
D) A and C
E) A and B

Question 49

Which amino acid will differentiate hemoglobin C disease from normal HbA?

A) Glycine
B) Leucine
C) Lysine
D) Arginine
E) Tyrosine

Question 50

Which abnormal hemoglobin migrates in the same position as HbA₂ on hemoglobin electrophoresis at alkaline pH?

A) HbF
B) HbC
C) HbS
D) HbG
E) HbD

Question 51

Which of the following is characteristic of hemoglobin SC disease?

A) Patients are generally less anemic than those with sickle cell anemia
B) Greater incidence of retinal hemorrhage
C) Greater incidence of renal papillary necrosis
D) Necrosis of the femoral head
E) All of the above

Question 52

Hemoglobin C disease is found almost exclusively in which population?

A) Caucasian
B) Black
C) Asian
D) Oriental
E) All of the above

Question 53

Most hemoglobin variant traits without coexisting conditions of iron-deficiency anemia or thalassemia have approximately what percentage ratio of normal to abnormal hemoglobin?

A) 50:50
B) 30:70
C) 60:40
D) 80:20
E) 40:60

Question 54

Which of the following may be found on the hemoglobin electrophoresis at alkaline pH?

A) 95% HbC plus HbA₂
B) No HbA (0%)
C) Less than 7% HbF
D) All of the above
E) None of the above

Question 55

What is the frequency of hemoglobin C disease in American blacks in the United States?

A) 2-3%
B) 1%
C) 0.02%
D) 15%
E) 28%

Question 56

Which of the following represents the only significant finding on the peripheral smear in hemoglobin C trait?

A) Targeting
B) Hemoglobin C crystals
C) Nucleated red cells
D) 4+ anisocytosis and poikilocytosis
E) All of the above

Question 57

Which of the following hematological results will suggest an individual with sickle cell trait?

A) Peripheral blood smear is normal with the exception of target cells
B) Solubility screening tests are positive
C) Hemoglobin electrophoresis demonstrates hemoglobin A, hemoglobin S, and usually slightly elevated hemoglobin A₂
D) Sickle cells present on the peripheral smear
E) A, B, and C

Question 58

Which of the following hemoglobins migrates to the same position as HbS on hemoglobin electrophoresis at alkaline pH?

A) HbD
B) HbC
C) HbG
D) A and C
E) B and C

Question 59

Hemoglobin D migrates in the position of what other hemoglobin on hemoglobin electrophoresis at alkaline pH?

A) HbS
B) HbA
C) HbA₂
D) HbC
E) HbE

Question 60

What percentage of American blacks carry the hemoglobin C trait?

A) 0.02%
B) 0.08%
C) 2-3%
D) 8-10%
E) 20%

Question 61

Which of the following is characteristic of methemoglobinemia?

A) The blood may be chocolate-brown depending on the severity.
B) Cyanosis may result depending on the severity.
C) Hemoglobin iron in the oxidized ferric state is unable to carry or to bind oxygen.
D) All of the above
E) None of the above

Question 62

Hemoglobin E occurs with the greatest frequency in which of the following populations?

A) Caucasian
B) Oriental
C) Black
D) Asian
E) Any of the above

Question 63

Which of the following is not characteristic of hemoglobin D disease?

A) Migrates electrophoretically in same position as hemoglobin S
B) Less than 0.02% frequency in American blacks
C) Both homozygous and heterozygous states are asymptomatic
D) Peripheral blood smear is unremarkable, except for a few target cells
E) Positive tube solubility test

Question 64

Which of the following is characteristic of hemoglobin E disease?

A) Red cell indices indicate a microcytic hypochromic anemia.
B) Target cells are found on the peripheral smear.
C) 95-97% HbE on the alkaline hemoglobin electrophoresis
D) No HbA
E) All of the above

Question 65

Which of the following represent(s) inherited high-affinity hemoglobins?

A) Hb Chesapeake
B) Hb Rainier
C) Hb Bethesda
D) Hb Hiroshima
E) All of the above

Question 66

Which of the following is characteristic of hemoglobin D disease?

A) Most common variant in American blacks is HbD Punjab (HbD Los Angeles)
B) Less than 0.02% frequency in American blacks
C) Both homozygous and heterozygous states are asymptomatic
D) Peripheral blood smear is unremarkable, except for a few target cells
E) All of the above

Question 67

Which of the following hemoglobins migrates in the same position as HbA₂ on hemoglobin electrophoresis at alkaline pH?

A) HbC
B) HbO Arab
C) HbE
D) All of the above
E) None of the above

Question 68

Which of the following is characteristic of inherited high-affinity hemoglobins?

A) Shift to the left of oxygen dissociation curve (low P₅₀ levels)
B) Erythrocytosis and polycythemia
C) Increase in hemoglobin, hematocrit, and RBC count
D) All of the above
E) None of the above

Question 69

Which of the following represents causes of methemoglobinemia?

A) Hemoglobin M variants
B) NADH-diaphorase deficiency
C) Toxic substance
D) All of the above
E) None of the above

Question 70

Which of the following may be associated with inherited decreased affinity hemoglobins?

A) Mild anemia
B) Cyanosis
C) Shift to the right of the oxygen-dissociation curve (high P₅₀ levels)
D) All of the above
E) None of the above

Question 71

Which of the following defines methemoglobin?

A) Hemoglobin with oxidized ferric iron (Fe³⁺)
B) Hemoglobin with ferrous iron (Fe²⁺)
C) Hemoglobin with carbon monoxide attached to heme
D) Hemoglobin with sulfide attached to heme
E) None of the above

Question 72

Methemoglobinemia is a clinical condition associated with levels greater than what percent of the total hemoglobin?

A) 0.1%
B) 1%
C) 0.01%
D) Any of the above
E) None of the above

Question 73

Which of the following is characteristic of hemoglobin O Arab?

A) A rare hemoglobin variant that occurs infrequently in black, Arab, and Sudanese populations
B) Exhibits a mild hemolytic anemia
C) Exhibits slight splenomegaly
D) Target cells present on the peripheral blood smear
E) All of the above

Question 74

Which of the following represents inherited decreased affinity hemoglobins?

A) Hb Chesapeake
B) HbS
C) HbC
D) Hb Kansas
E) Hb Rainier

Question 75

Which of the following should patients be promptly treated with for acquired methemoglobinemia?

A) Intravenous methylene blue (a strong reducing substance)
B) Oxygen administration
C) Exchange transfusion
D) All of the above
E) None of the above