W1-10 Hemogloinopathies and associated anemias
73 Questions
3 Views

Choose a study mode

Play Quiz
Study Flashcards
Spaced Repetition
Chat to lesson

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

Which of the following is the underlying mutation in HbC disease?

  • Polymorphism in the α-globin gene
  • Insertion mutation in the γ-globin gene
  • Deletion of the β-globin gene
  • Point mutation (Glu —> Val at amino acid 6) in β-globin (HBB) gene (correct)
  • What is the major cause of pathogenesis in sickle cell disease?

  • Decreased production of RBCs
  • Polymerization of deoxygenated HbS (correct)
  • Disruption of RBC membrane integrity
  • Oxidative damage to hemoglobin
  • What type of anemia is sickle cell disease?

  • Aplastic anemia
  • Macrocytic hyperchromic anemia
  • Microcytic hypochromic anemia
  • Normocytic hemolytic anemia with extravascular hemolysis (correct)
  • Which population is primarily affected by sickle cell disease?

    <p>African Americans</p> Signup and view all the answers

    What is the genetic nature of sickle cell disease?

    <p>Autosomal recessive disorder</p> Signup and view all the answers

    What proportion of sickled RBCs undergo intravascular hemolysis?

    <p>A small proportion</p> Signup and view all the answers

    Which condition is characterized by the loss of three α-globin genes, relative excess of β-globin chains, and the formation of stable β4 tetramers?

    <p>HbH disease</p> Signup and view all the answers

    What is the consequence of deletion of all four α-globin genes?

    <p>Lethal in utero due to virtually no oxygen-delivering capacity</p> Signup and view all the answers

    In which condition does the excess in γ-globin chains lead to the formation of γ4 tetramers (Hb Barts)?

    <p>Hydrops fetalis</p> Signup and view all the answers

    Which condition is characterized by the proportional severity of the disease to the number of missing α-globin genes?

    <p>Silent carrier state</p> Signup and view all the answers

    Which test is considered the best for diagnosing sickle cell disease?

    <p>High performance liquid chromatography (HPLC)</p> Signup and view all the answers

    What is the characteristic feature seen in HbC disease on peripheral blood smear (PBS)?

    <p>HbC crystals</p> Signup and view all the answers

    What is the clinical behavior of HbSC disease?

    <p>Similar to sickle cell anemia (SCA) but with a milder clinical course</p> Signup and view all the answers

    What demographic is endemic for thalassemias?

    <p>Mediterranean, African, and Asian regions</p> Signup and view all the answers

    Which type of thalassemia is characterized by decreased/absent α-globin chains with excess of β-globin chains?

    <p>Alpha-thalassemia</p> Signup and view all the answers

    What is the primary mechanism of anemia in β-thalassemia?

    <p>Inadequate HbA formation</p> Signup and view all the answers

    What is the characteristic feature of HbC disease in terms of erythrocyte morphology?

    <p>Target cells with increased MCHC</p> Signup and view all the answers

    Which test is used in review books but is not clinically indicated for screening or managing sickle cell disorders?

    <p>&quot;Sickledex&quot; sodium metabisulfite test</p> Signup and view all the answers

    What does the presence of Howell-Jolly bodies in patients with sickle cell anemia indicate?

    <p>Hyposplenism or autosplenectomy</p> Signup and view all the answers

    What is the result of a high serum bilirubin level in patients with sickle cell anemia?

    <p>Intravascular hemolysis</p> Signup and view all the answers

    What feature distinguishes HbSC disease from sickle cell anemia (SCA)?

    <p>Presence of nucleated RBCs in peripheral blood smear (PBS)</p> Signup and view all the answers

    What is the primary consequence of excess unpaired α-chains in β-thalassemia?

    <p>Production of insoluble hemoglobin precipitates</p> Signup and view all the answers

    What is the primary event in the pathogenesis of β-thalassemia?

    <p>Destruction of erythroid precursors</p> Signup and view all the answers

    In β-thalassemia, what results in extensive extramedullary hematopoiesis and hepato- and splenomegaly?

    <p>Erythroferrone release</p> Signup and view all the answers

    What is the genetic basis for the clinical classification of β-thalassemia?

    <p>Severity of anemia and gene defect</p> Signup and view all the answers

    Which type of β-thalassemia is characterized by severe anemia but does not require regular blood transfusions?

    <p>β-thal intermedia</p> Signup and view all the answers

    What is a characteristic morphological change in the peripheral blood smear (PBS) of β-thalassemia major?

    <p>Microcytic, hypochromic cells with basophilic stippling</p> Signup and view all the answers

    What is a common complication in β-thalassemia that leads to 'bronze diabetes'?

    <p>Secondary hemochromatosis</p> Signup and view all the answers

    What is the cause of α-thalassemia?

    <p>Deletion of one or more α-globin genes</p> Signup and view all the answers

    In α-thalassemia, which type of genetic deletion results in the most severe manifestations?

    <p>-- -- -- +</p> Signup and view all the answers

    What type of hemoglobin is predominant in normal adult individuals?

    <p>HbA/HbA</p> Signup and view all the answers

    Which type of Hb spectrum (%) is characteristic of sickle cell trait?

    <p>HbA/HbS</p> Signup and view all the answers

    What are the predominant types of hemoglobin in sickle cell trait?

    <p>HbS/HbC</p> Signup and view all the answers

    What is the most common manifestation of vaso-occlusion in sickle cell disease?

    <p>Acute chest syndrome</p> Signup and view all the answers

    What is the primary cause of death in children with sickle cell disease?

    <p>Infection with encapsulated bacteria</p> Signup and view all the answers

    What does the presence of Howell-Jolly bodies on peripheral blood smear indicate in sickle cell disease?

    <p>Autosplenectomy</p> Signup and view all the answers

    What is the common cause of death in adults with sickle cell disease?

    <p>Acute chest syndrome</p> Signup and view all the answers

    What condition results from the infection of red cell progenitors by parvovirus B19 in sickle cell disease?

    <p>Aplastic crisis</p> Signup and view all the answers

    Which manifestation in sickle cell disease is characterized by rapid splenic enlargement, hypovolemia, and shock?

    <p>Sequestration crisis</p> Signup and view all the answers

    What is the primary cause of chronic anemia in sickle cell anemia?

    <p>Irreversible sickled RBCs</p> Signup and view all the answers

    Which type of crisis in sickle cell disease is associated with an acute drop in hemoglobin and high reticulocyte count?

    <p>Hyperhemolytic crisis</p> Signup and view all the answers

    What is the characteristic bone change seen in individuals with sickle cell anemia?

    <p>&quot;Crew-cut&quot; appearance on skull x-ray</p> Signup and view all the answers

    "Dactylitis" (hand-foot syndrome) in infants with sickle cell disease is characterized by:

    <p>Bone infarcts with swelling of hands and feet</p> Signup and view all the answers

    What is the primary consequence of deletion of all four α-globin genes?

    <p>Excess of γ-globin and formation of γ-globin tetramers (Hb Barts)</p> Signup and view all the answers

    What is the characteristic morphological change in the peripheral blood smear (PBS) of HbH Disease?

    <p>HbH aggregates</p> Signup and view all the answers

    What condition results from a decline in Hb Portland production in Trimester 3?

    <p>Hydrops fetalis</p> Signup and view all the answers

    Which manifestation is characteristic of Hb Barts Disease?

    <p>Severe pallor, generalized edema, and massive hepatosplenomegaly</p> Signup and view all the answers

    What is the clinical presentation of α-Thal: Hb Barts Disease (-/- -/-)?

    <p>Severe pallor, generalized edema, and massive hepatosplenomegaly</p> Signup and view all the answers

    What does the excess in γ-globin chains lead to in Hb Barts Disease?

    <p>Formation of γ-globin tetramers (Hb Barts)</p> Signup and view all the answers

    What is the primary mechanism of anemia in β-thalassemia?

    <p>Reduced hemoglobin synthesis</p> Signup and view all the answers

    What is the characteristic bone change seen in individuals with sickle cell anemia?

    <p>Avascular necrosis of the hip</p> Signup and view all the answers

    What is the consequence of deletion of all four α-globin genes?

    <p>Hydrops fetalis</p> Signup and view all the answers

    Which condition exhibits manifestations similar to β-thalassemia minor?

    <p>Alpha-thalassemia trait</p> Signup and view all the answers

    What is the genetic nature of sickle cell disease?

    <p>Autosomal recessive</p> Signup and view all the answers

    What is the clinical behavior of HbSC disease?

    <p>More severe than HbAS but milder than HbSS</p> Signup and view all the answers

    Which type of crisis in sickle cell disease is associated with an acute drop in hemoglobin and high reticulocyte count?

    <p>Aplastic crisis</p> Signup and view all the answers

    What is the common cause of death in adults with sickle cell disease?

    <p>Acute chest syndrome</p> Signup and view all the answers

    Which type of thalassemia is characterized by decreased/absent α-globin chains with excess of β-globin chains?

    <p>Beta-thalassemia minor</p> Signup and view all the answers

    What is the primary event in the pathogenesis of β-thalassemia?

    <p>Reduced hemoglobin synthesis</p> Signup and view all the answers

    What demographic is endemic for thalassemias?

    <p>Mediterranean and Southeast Asians</p> Signup and view all the answers

    Which population is primarily affected by sickle cell disease?

    <p>Africans and African Americans</p> Signup and view all the answers

    Which type of hemoglobin is predominant in normal adult individuals?

    <p>HbA</p> Signup and view all the answers

    What is the primary cause of chronic anemia in sickle cell anemia?

    <p>Vaso-occlusion</p> Signup and view all the answers

    What is the genetic basis for the clinical classification of β-thalassemia?

    <p>Reduced expression of beta-hemoglobin</p> Signup and view all the answers

    What feature distinguishes HbSC disease from sickle cell anemia (SCA)?

    <p>Different types of hemoglobin present</p> Signup and view all the answers

    What is the primary pathophysiological mechanism in β-thalassemia major?

    <p>Severely reduced production of β-Hb chains</p> Signup and view all the answers

    In β-thalassemia, what is the specific consequence of the surplus of β-like chains?

    <p>Formation of homo-tetramers</p> Signup and view all the answers

    What is the characteristic phenotype of HbE/HbE homozygotes?

    <p>Mild hypochromic, microcytic anemia</p> Signup and view all the answers

    Which type of thalassemia exhibits a mixed process as it changes both the content and amount of protein?

    <p>HbE/ -thalassemia compound heterozygotes</p> Signup and view all the answers

    What is the primary consequence of deletion of all four α-globin genes?

    <p>Surplus production of γ-Hb chains</p> Signup and view all the answers

    What is the underlying mutation in HbC disease?

    <p>Substitution GAG-to-AAG in codon 26 leading to Glu26Lys</p> Signup and view all the answers

    What is the characteristic feature seen in HbC disease on peripheral blood smear (PBS)?

    <p>Presence of Howell-Jolly bodies</p> Signup and view all the answers

    Which condition results from the infection of red cell progenitors by parvovirus B19 in sickle cell disease?

    <p>-Thalassemia trait</p> Signup and view all the answers

    Study Notes

    • The text discusses sickle cell disease (SCD) and associated anemias, with a focus on sickle cell disease, HbC disease, and β- and α-thalassemia.
    • Sickle cell disease is a normocytic hemolytic anemia with extravascular hemolysis, affecting African Americans and caused by a point mutation in the β-globin gene (HBB).
    • The disease results from the formation of sickle polymers when HbS deoxygenates, leading to sickled RBCs and various complications.
    • Sickle cell anemia (homozygosity) presents with severe anemia, irreversible sickled RBCs, and frequent crises, while sickle cell trait (heterozygosity) is usually asymptomatic.
    • Enhancing factors for sickling include hypoxia, dehydration, acidosis, and high altitude, while preventive factors include HbF and hydroxyurea.
    • Sickle cell disease crises include vaso-occlusive, sequestration, aplastic, and hyperhemolytic, each presenting with distinct clinical features and complications.
    • Vaso-occlusive crises result from vaso-occlusion and ischemia caused by sickled RBCs, leading to pain, infarctions, and organ damage.
    • Sequestration crisis occurs in children with an intact spleen, resulting in rapid splenic enlargement, hypovolemia, and shock.
    • Aplastic crisis is caused by infection of red cell progenitors by parvovirus B19, leading to transient cessation of erythropoiesis and worsening anemia.
    • Hyperhemolytic crisis is characterized by an acute drop in hemoglobin and high reticulocyte count, often resulting from infection or other stressors.
    • Complications of sickle cell disease include splenic infarcts, infections, and bone changes, as well as damage to various organs.
    • Treatments for sickle cell disease include supportive care, hydroxyurea, and bone marrow transplantation, while prevention includes newborn screening, gene therapy, and vaccinations.
    • SCD can lead to chronic anemia, jaundice, pigmented gallstones, and reticulocytosis, as well as crises and organ damage if left untreated.
    • HbC disease is caused by a different mutation in the β-globin gene, leading to the production of HbC and HbE, which form inclusions in RBCs.
    • β- and α-thalassemia are genetic disorders affecting the production of β- or α-globin chains, respectively, leading to various hemoglobin abnormalities and complications.

    Studying That Suits You

    Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

    Quiz Team

    Description

    Explore the etiology, pathogenesis, morphological changes, clinical presentation, complications, laboratory data, treatment, and prognosis of sickle cell disease. Understand the implications of splenic infarct and Howell-Jolly bodies.

    More Like This

    Sickle Cell Disease Overview
    15 questions
    Sickle Cell Disease
    6 questions

    Sickle Cell Disease

    ThumbUpLagrange avatar
    ThumbUpLagrange
    Sickle Cell Disease and Thalassemia
    30 questions
    Sickle Cell Disease Pathophysiology
    8 questions
    Use Quizgecko on...
    Browser
    Browser