Sickle cell anemia MCQs With Answer

Sickle cell anemia MCQs With Answer — This concise, keyword-rich introduction is designed for B.Pharm students studying sickle cell disease, pharmacotherapy, and pathophysiology. Learn essential concepts such as hemoglobin S mutation, polymerization of deoxygenated HbS, vaso-occlusive crises, acute chest syndrome, and complications like splenic sequestration and stroke. Review diagnostic tools (HPLC, peripheral smear), preventive strategies (newborn screening, penicillin, vaccines), and current treatments including hydroxyurea, chronic transfusion, iron chelation, hematopoietic stem cell transplant, and new drugs like voxelotor and crizanlizumab. Strengthen clinical reasoning for pharmacologic management and monitoring. Now let’s test your knowledge with 50 MCQs on this topic.

Q1. Which genetic mutation causes sickle cell anemia?

• A point mutation in the beta-globin gene resulting in glutamic acid to valine substitution at codon 6
• A deletion of the alpha-globin gene resulting in alpha-thalassemia
• A frameshift mutation in the gamma-globin gene
• A nonsense mutation in the delta-globin gene

Correct Answer: A point mutation in the beta-globin gene resulting in glutamic acid to valine substitution at codon 6

Q2. What is the inheritance pattern of sickle cell disease (HbSS)?

• Autosomal dominant
• X-linked recessive
• Autosomal recessive
• Mitochondrial inheritance

Correct Answer: Autosomal recessive

Q3. Which hemoglobin variant is primarily responsible for sickling?

• Hemoglobin A
• Hemoglobin F
• Hemoglobin S
• Hemoglobin C

Correct Answer: Hemoglobin S

Q4. What is the fundamental molecular mechanism that leads to red blood cell sickling?

• Oxidative damage to membrane lipids
• Polymerization of deoxygenated hemoglobin S
• Autoimmune hemolysis due to antibody binding
• Excessive erythropoietin stimulation

Correct Answer: Polymerization of deoxygenated hemoglobin S

Q5. Which condition most directly promotes polymerization and sickling of HbS?

• Hyperoxia (high oxygen tension)
• Normothermia
• Deoxygenation and low oxygen tension
• Increased fetal hemoglobin levels

Correct Answer: Deoxygenation and low oxygen tension

Q6. Approximately how long is the lifespan of a sickled red blood cell compared with a normal RBC?

• 120 days, same as normal RBC
• 10–20 days, markedly reduced
• 60–80 days, moderately reduced
• Over 200 days, increased lifespan

Correct Answer: 10–20 days, markedly reduced

Q7. The hallmark clinical manifestation of vaso-occlusive crisis (VOC) is:

• Chronic cough and hemoptysis
• Painful episodes due to microvascular occlusion in bone and soft tissues
• Painless hematuria only
• Asymptomatic anemia without pain

Correct Answer: Painful episodes due to microvascular occlusion in bone and soft tissues

Q8. How is acute chest syndrome (ACS) in sickle cell disease best described?

• Chronic interstitial lung disease without infiltrate
• New pulmonary infiltrate on chest X‑ray with chest pain, fever or hypoxia
• Upper airway obstruction due to splenic enlargement
• Bronchospasm unrelated to infection or infarction

Correct Answer: New pulmonary infiltrate on chest X‑ray with chest pain, fever or hypoxia

Q9. Splenic sequestration crises are most commonly seen in which patient group?

• Older adults with long-standing disease
• Infants and young children
• Adolescents after puberty
• Only in patients with sickle cell trait

Correct Answer: Infants and young children

Q10. Which laboratory method is commonly used for definitive newborn screening and diagnosis of sickle cell disease?

• Complete blood count alone
• High-performance liquid chromatography (HPLC) or hemoglobin electrophoresis
• Direct antiglobulin (Coombs) test
• Peripheral blood culture

Correct Answer: High-performance liquid chromatography (HPLC) or hemoglobin electrophoresis

Q11. Typical peripheral blood smear findings in sickle cell anemia include:

• Macro-ovalocytes and hypersegmented neutrophils
• Sickle-shaped RBCs, target cells, and Howell-Jolly bodies
• Basophilic stippling only
• Ring sideroblasts

Correct Answer: Sickle-shaped RBCs, target cells, and Howell-Jolly bodies

Q12. The traditional sickling (metabisulfite) test induces sickling by:

• Raising oxygen tension
• Lowering oxygen tension using sodium metabisulfite
• Adding iron chelators
• Increasing pH to alkalinize the sample

Correct Answer: Lowering oxygen tension using sodium metabisulfite

Q13. Hydroxyurea reduces vaso-occlusive events primarily by:

• Chelating iron to reduce oxidative stress
• Stimulating production of fetal hemoglobin (HbF)
• Blocking P-selectin mediated adhesion
• Inhibiting platelet aggregation

Correct Answer: Stimulating production of fetal hemoglobin (HbF)

Q14. The most important adverse effect to monitor with hydroxyurea therapy is:

• Nephrotoxicity with rising creatinine
• Myelosuppression (neutropenia, thrombocytopenia)
• Ototoxicity
• Hypoglycemia

Correct Answer: Myelosuppression (neutropenia, thrombocytopenia)

Q15. A primary indication for initiating hydroxyurea in adolescents and adults with sickle cell disease is:

• Mild anemia without pain
• Frequent painful vaso-occlusive crises significantly affecting quality of life
• Asymptomatic sickle cell trait
• Uncomplicated urinary tract infection

Correct Answer: Frequent painful vaso-occlusive crises significantly affecting quality of life

Q16. Which oral iron chelator is commonly used to manage transfusional iron overload in sickle cell patients?

• Deferoxamine (only intravenous)
• Deferasirox (oral iron chelator)
• Deferiprone (intramuscular only)
• Desferral (no clinical use)

Correct Answer: Deferasirox (oral iron chelator)

Q17. Prophylactic penicillin is recommended for infants with sickle cell disease until approximately:

• 6 months of age
• 2 years of age
• 5 years of age
• Adulthood

Correct Answer: 5 years of age

Q18. Which vaccine is particularly emphasized for patients with sickle cell disease due to functional asplenia?

• Influenza vaccine only
• Pneumococcal vaccines (conjugate and polysaccharide)
• Yellow fever vaccine
• HPV vaccine only

Correct Answer: Pneumococcal vaccines (conjugate and polysaccharide)

Q19. The only widely accepted curative therapy for sickle cell anemia at present is:

• Long-term hydroxyurea monotherapy
• Allogeneic hematopoietic stem cell (bone marrow) transplant
• Regular phlebotomy
• Iron chelation therapy

Correct Answer: Allogeneic hematopoietic stem cell (bone marrow) transplant

Q20. Modern gene therapy approaches for sickle cell disease aim to:

• Increase iron absorption in the gut
• Correct the HBB mutation or induce anti‑sickling globin expression
• Enhance platelet production
• Reduce erythropoietin secretion

Correct Answer: Correct the HBB mutation or induce anti‑sickling globin expression

Q21. First-line pharmacologic management for severe acute vaso-occlusive pain includes:

• Oral iron and folic acid only
• Opioid analgesics, hydration, and supportive care
• Immediate splenectomy
• High-dose corticosteroids as sole therapy

Correct Answer: Opioid analgesics, hydration, and supportive care

Q22. Chronic transfusion therapy is indicated primarily to prevent which major complication?

• Acute chest syndrome
• Stroke in high-risk children identified by TCD screening
• Pulmonary embolism
• Hyaline membrane disease

Correct Answer: Stroke in high-risk children identified by TCD screening

Q23. The preferred acute treatment for a patient with sickle cell disease who presents with an ischemic stroke is:

• Simple transfusion to raise hemoglobin by 1 g/dL
• Exchange transfusion to reduce HbS percentage quickly
• No transfusion, only aspirin
• Immediate hydroxyurea loading dose

Correct Answer: Exchange transfusion to reduce HbS percentage quickly

Q24. Which statement best describes hydroxyurea use during pregnancy?

• Hydroxyurea is safe and routinely started in pregnancy
• Hydroxyurea is generally avoided due to potential teratogenicity
• Hydroxyurea should be doubled during pregnancy
• Hydroxyurea prevents all pregnancy-related complications in SCD

Correct Answer: Hydroxyurea is generally avoided due to potential teratogenicity

Q25. Prenatal diagnosis for sickle cell disease can be achieved by which method?

• Maternal serum ferritin measurement
• Chorionic villus sampling or amniocentesis with fetal DNA analysis for HBB mutation
• Routine ultrasound at 20 weeks alone
• Fetal hemoglobin electrophoresis in maternal blood

Correct Answer: Chorionic villus sampling or amniocentesis with fetal DNA analysis for HBB mutation

Q26. Hemoglobin electrophoresis in a patient with sickle cell anemia (HbSS) typically shows:

• Predominant HbA with absent HbS
• Predominant HbS with increased HbF and absent HbA
• Only HbF present
• Predominant HbA2 only

Correct Answer: Predominant HbS with increased HbF and absent HbA

Q27. Supplemental oxygen is used in acute sickle cell complications primarily to:

• Normalize hemoglobin concentration
• Reduce deoxygenation-induced sickling in tissues during crises
• Increase red cell production in bone marrow
• Directly dissolve hemoglobin polymers

Correct Answer: Reduce deoxygenation-induced sickling in tissues during crises

Q28. Over time, repeated splenic infarctions in sickle cell disease usually result in:

• Splenic enlargement and hyperfunction
• Functional asplenia or autosplenectomy
• Acute splenic rupture as a universal outcome
• Complete regeneration of splenic tissue

Correct Answer: Functional asplenia or autosplenectomy

Q29. The most appropriate immediate invasive treatment for ischemic priapism in sickle cell disease is:

• Oral sildenafil and observation
• Intracavernosal injection of phenylephrine and corporal aspiration
• Immediate penile amputation
• Subcutaneous terbutaline only

Correct Answer: Intracavernosal injection of phenylephrine and corporal aspiration

Q30. Dactylitis (hand-foot syndrome) is most typically seen in which age group with sickle cell disease?

• Neonates in the first week only
• Infants and young children
• Elderly patients over 65
• Only in adults with sickle cell trait

Correct Answer: Infants and young children

Q31. Typical mean corpuscular volume (MCV) in untreated sickle cell disease is usually:

• Low (microcytic)
• Normal or slightly elevated (normocytic to macrocytic)
• Very high (>120 fL) in all patients
• Indeterminate and never useful

Correct Answer: Normal or slightly elevated (normocytic to macrocytic)

Q32. L-glutamine therapy in sickle cell disease is believed to work by:

• Chelating iron to reduce overload
• Reducing oxidative stress and improving red cell redox potential
• Directly breaking HbS polymers
• Stimulating erythropoietin secretion

Correct Answer: Reducing oxidative stress and improving red cell redox potential

Q33. Pulmonary hypertension in sickle cell disease is most closely associated with:

• Iron deficiency anemia
• Chronic hemolysis leading to nitric oxide scavenging and endothelial dysfunction
• Excessive hydroxyurea use
• Primary pulmonary infections only

Correct Answer: Chronic hemolysis leading to nitric oxide scavenging and endothelial dysfunction

Q34. Which of the following is a common indication for splenectomy in sickle cell patients?

• Asymptomatic mild splenic enlargement without hemoglobin drop
• Recurrent painful splenic sequestration with risk of hypovolemia
• Prevention of vaso-occlusive crises in adults
• Routine management of acute chest syndrome

Correct Answer: Recurrent painful splenic sequestration with risk of hypovolemia

Q35. What happens to the reticulocyte count in sickle cell anemia during steady-state hemolysis?

• It is decreased due to bone marrow suppression
• It is elevated as marrow response to chronic hemolysis
• Remains unchanged from normal
• Reticulocytes are absent

Correct Answer: It is elevated as marrow response to chronic hemolysis

Q36. If both parents are carriers of sickle cell trait (HbAS), what is the risk for each pregnancy of having a child with sickle cell disease (HbSS)?

• 0% (no risk)
• 25% chance
• 50% chance
• 100% chance

Correct Answer: 25% chance

Q37. Newborn screening for sickle cell disease is usually performed within what timeframe after birth?

• 24–48 hours of life through heel-prick screening
• At 6 months only
• Only if symptoms develop after 2 years
• At puberty

Correct Answer: 24–48 hours of life through heel-prick screening

Q38. The best donor source for allogeneic hematopoietic stem cell transplant in sickle cell disease is usually:

• An unrelated donor with mismatched HLA
• An HLA-matched sibling donor
• Autologous peripheral blood stem cells without gene modification
• Any first-degree relative regardless of HLA match

Correct Answer: An HLA-matched sibling donor

Q39. Which process contributes to increased vaso-occlusion in sickle cell disease?

• Decreased endothelial adhesion molecule expression
• Increased adhesion of sickled RBCs and leukocytes to endothelium mediated by adhesion molecules
• Reduced inflammation and leukocyte activation
• Enhanced nitric oxide bioavailability

Correct Answer: Increased adhesion of sickled RBCs and leukocytes to endothelium mediated by adhesion molecules

Q40. Common precipitants of acute chest syndrome include:

• Inhalation of helium only
• Pulmonary infection and fat embolism from bone marrow necrosis
• Exclusive overuse of hydroxyurea
• Isolated splenic infarction without lung involvement

Correct Answer: Pulmonary infection and fat embolism from bone marrow necrosis

Q41. Why do clinical symptoms of sickle cell disease typically appear several months after birth?

• Newborns have a permanent supply of adult hemoglobin A
• High levels of fetal hemoglobin (HbF) in infancy protect against sickling until HbF declines
• RBCs do not produce hemoglobin until after 1 year
• Maternal antibodies prevent symptoms throughout infancy

Correct Answer: High levels of fetal hemoglobin (HbF) in infancy protect against sickling until HbF declines

Q42. Which statement best characterizes individuals with sickle cell trait (HbAS)?

• They always have severe hemolytic anemia
• They are generally asymptomatic but may have hematuria or renal medullary issues under extreme conditions
• They require lifelong transfusions
• They have absent HbA and only HbS

Correct Answer: They are generally asymptomatic but may have hematuria or renal medullary issues under extreme conditions

Q43. Hemoglobin electrophoresis pattern in sickle cell trait (HbAS) typically shows:

• Only HbS present
• Predominant HbA with a significant proportion of HbS
• Only HbA present
• Predominant HbF only

Correct Answer: Predominant HbA with a significant proportion of HbS

Q44. Chronic vaso-occlusive damage in sickle cell disease most commonly affects which organs?

• Skin only
• Bones, spleen, lungs, and brain leading to osteonecrosis, autosplenectomy, pulmonary complications, and stroke
• Thyroid and parathyroid glands only
• Pancreas exclusively

Correct Answer: Bones, spleen, lungs, and brain leading to osteonecrosis, autosplenectomy, pulmonary complications, and stroke

Q45. What laboratory monitoring is essential for patients on hydroxyurea therapy?

• Monthly liver biopsy
• Regular complete blood counts with differential to monitor for cytopenias
• Daily serum iron levels
• No monitoring is required once started

Correct Answer: Regular complete blood counts with differential to monitor for cytopenias

Q46. Which methods are commonly used to monitor iron overload in chronically transfused patients?

• Serum ferritin measurements and MRI T2* of liver and heart
• Only CBC monitoring
• Bone marrow biopsy monthly
• Urine calcium levels

Correct Answer: Serum ferritin measurements and MRI T2* of liver and heart

Q47. Major complications of chronic transfusion therapy include:

• Hypersplenism and decreased infections only
• Alloimmunization and iron overload requiring chelation
• Complete cure of the disease without risks
• Immediate reversal of genetic mutation

Correct Answer: Alloimmunization and iron overload requiring chelation

Q48. Increasing levels of fetal hemoglobin (HbF) reduce sickling because HbF:

• Increases polymer formation of HbS
• Inhibits HbS polymerization and reduces intracellular sickling tendency
• Depletes iron stores
• Causes immediate hemolysis

Correct Answer: Inhibits HbS polymerization and reduces intracellular sickling tendency

Q49. Basic supportive measures in an acute vaso-occlusive crisis include:

• Immediate high-dose aspirin as the only treatment
• Adequate hydration, effective analgesia, and oxygen as needed
• Isolated antibiotic therapy without analgesia or fluids
• Routine iron infusion

Correct Answer: Adequate hydration, effective analgesia, and oxygen as needed

Q50. Voxelotor, a newer drug approved for sickle cell disease, primarily works by:

• Blocking P-selectin mediated adhesion of cells
• Increasing hemoglobin’s affinity for oxygen to inhibit HbS polymerization
• Acting as an iron chelator to treat overload
• Stimulating bone marrow to produce more leukocytes

Correct Answer: Increasing hemoglobin’s affinity for oxygen to inhibit HbS polymerization

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