Please confirm topic selection

Are you sure you want to trigger topic in your Anconeus AI algorithm?

Please confirm action

You are done for today with this topic.

Would you like to start learning session with this topic items scheduled for future?

Updated: Dec 30 2021

Thalassemias

Images
https://upload.medbullets.com/topic/120224/images/targetcell.jpg
https://upload.medbullets.com/topic/120224/images/differential for anemia - moises d.jpg
  • Snap Shot
    • A 22-year-old Vietnamese female presents for a routine gyn exam. Her menstrual cycle is normal and there is no evidence of other bleeding. Guiac is negative. Her hemoglobin is at 11 (12-16), RBC is 5.8 (3.5-5.5), and an MCV of 70 (80-100) with a normal RDW of 10. WBC and platelets are normal. Hemoglobin electrophoresis shows an increase in amount of Hgb A2 and Hgb F.
  • Introduction
    • Hereditary disease caused by decreased production of hemoglobin chains
    • Most common cause of microcytic anemia in Asian Americans and African Americans
    • There are four alpha genes and two beta genes that make up three forms of hemoglobin (Hgb)
        • Hgb Form
        • Subunits
        • Prevalence
        • Hgb A
        • alpha, alpha, beta, beta
        • 96-98% of adult hemoglobin
        • Hgb A2
        • alpha, alphadelta, delta
        • Present in trace amounts in adults
        • Hgb F
        • alpha, alpha, gamma, gamma
        • Declines in the first year of life
  • STUDIES
    • Ratio used:
      • Mentzer Ratio = MCV / RBC
        • if it is less than 13 it is highly predictive of thalassemia
        • greater than 13 indicates an iron deficiency or anemia of inflammation
    • Lab findings
      • MCV - profoundly decreased
      • TIBC - decreased
      • iron - increased
      • ferretin - increased
      • reticulocyte count - increased
      • transferrin saturation - increased
  • DIAGNOSIS
    • Forms of disease diagnosed through gel-electrophoresis of globin chains
    • Unexplained finding is that although there is a decrease in the Hgb concentration and MCV, there is a normal or slightly increased RBC count
  • Alpha Thalassemia
    • Due to a decrease in alpha globin chain production
    • Seen commonly in Asians
      • less common in Africans and Mediterranean
        • Affected alleles
        • Disease
        • Characteristics
        • Evaluation
        • 1/4
        • Carrier state
        • Asymptomatic
        • Normal
        • 2/4
        • Alpha Thal. minor
        • Normal life expectancy
        • Mild microcytic anemia
        • 3/4
        • Hgb H disease
        • Associated with chronic hemolytic anemia, pallor, and splenomegaly. May require occasional transfusion
        • Hgb H (beta tetramer) and Bart's Hgb (gamma tetramer) on electrophoresis
        • 4/4
        • Hydrops fetalis
        • Fetal demise with total body edema
        • Bart's beta-4 Hgb precipitations
  • Beta Thalassemia
    • Beta thalasemia is more common in people of Mediterranean or African origin
    • Function of beta chain required at six months when switch from fetal y Hgb to adult beta Hgb occurs
        • Affected alleles
        • Disease
        • Characteristics
        • Evaluation
        • Treatment
        • 1/2
        • Asymptomatic carrier
        • Decreased Hgb A, increased Hgb A2(y) and normal Hgb F
        • Avoid oxidative stress, treat with folate and transfusions during severe anemia and pregnancy
        • 2/2
        • Thalassemia major 
        • Anemia develops at six months as Hgb F declines, frontal bossing from extramedullary hematopoiesis, and splenomegly
        • No Hgb A,  increased Hgb A2, and Hgb F on electrophoresis
        • Splenectomy, folate supplementation, and transfusions. Symptoms improve with transfusions, patients usually die from transfusion iron overload (heart and liver failure).
Card
1 of 0
Question
1 of 6
Private Note

Attach Treatment Poll
Treatment poll is required to gain more useful feedback from members.
Please enter Question Text
Please enter at least 2 unique options
Please enter at least 2 unique options
Please enter at least 2 unique options