Anaemias Flashcards
(8 cards)
What are the roles of B6, 9 and 12 in RBC development?
B6- supports hemoglobin production
B9- crucial for DNA synthesis and RBC cell division
B12- important for RBC maturation and DNA synthesis
What anemias arise from the lack of B6, 9 & 12?
B6- Sideroblastic, impaired heme production , leads to ineffective RBC production and prescence of abnormal RBC precursors
B9- Megaloblastic, imparied DNA synthesis, lead to the prodcution of immature RBCs
B12- Pernicious, disrupted DNA sytnhesis and RBC matruation, large immature RBCs produced
Why does a lack of intrinsic factor lead to megaloblastic anaemia?
intrinsic factor binds to Vit B12 in the stomach for absorption
Without IF , B12 cannot be absorbed
Without B12, RBCs become large, immature (megaloblasts) and ineffective
Give 3 causes of acquired siderblastic anaemia?
- Alcoholism- toxic to the bone marrow, interferes with heme synthesis
- Drug toxicity- interfere with heme production
- Nutritional deficiencies- Vit B6 deficiency impairs the enzyme ALA synthetase
What are the consequences of detected antibodies that bind to intrinsic factor in a patient with anaemia?
- Impaired Vit B12 absorbtion
- Vit B 12 deficiency
- Megaloblastic anemia
A 3-year-old boy is identified to have a Glu→Val substitution at the 6th amino acid on the beta globin protein. What disorder is the most likely diagnosis?
Substitution is the hallmark of sickle cell disease
Mutation causes producvtion of hemoglobin S, which under low oxygen condtions, forms sickle-shaped RBCs
Briefly describe the differences in mutations that result in alpha and beta thalassemia
Alpha- affects alpha-globin production (chromosome 16)
Beta- affects beta-globin production (chromosome 11)
Briefly describe how malaria can lead to anaemia
RBC destruction- parasites infect and rupture RBC
Bone marrow supression- immune resposne supresses RBC production
Decreased RBC lifespan
Immune hemolysis- anitbodies attack infected and uninfected RBC’s
