Inherited Anemias Flashcards
(44 cards)
______ is an inherited hemoglobinopathy in which a genetic mutation leads to abnormal hemoglobin
Sickle Cell Disease
Inheritence pattern of sickle cell disease
autosomal recessive; most common in those of african descent
____ black children in the US are born
homozygous for Hgb S (Sickle Cell Disease)
1 in 400
heterozygous for Hgb S
Sickle cell trait
Pathophysiology of sickle cell disease
Hemoglobin S is unstable and will
polymerize in the setting of various stressors, such as hypoxic tissue and acidosis
● This polymerization leads to the
Sickle-shaped RBCs
Sickled cells have difficulty passing through small capillaries, which can lead to ____
blockage and tissue necrosis
Sickled cells are either destroyed in
peripheral circulation or by the spleen,
resulting in _____
Hemolytic Anemia
Free Hgb from hemolysis causes ____
endothelial dysfunction, vascular injury, and pulmonary hypertension
Early S/S sickle cell disease
● Early signs can include delayed growth and development, fevers, and
splenomegaly
○ Recurrent infections start occurring with hyposplenism
When is Hgb F present?
first 6-12 months of life
Babies born with Sickle Cell Disease present with symptoms at about
6-12 months of age when fetal hemoglobin (Hgb F) is replaced by Hgb S
Decreased Hgb S affinity for O2 and endovascular damage can cause
_____
pulmonary hypertension, CHF, etc.
How can multi-organ failure occur in sickle cell disease?
Repeated episodes of vascular occlusion especially affect the heart, lungs, and liver
○ Multisystem organ failure, heart failure, stroke, and osteonecrosis are all possible and common complications
Patients with Sickle Cell Trait do not have clinical disease unless they
are exposed to an episode of ____
significant hypoxia
Clinical management if a patient presents with a sickle cell crisis
○ Hydration (often IV)
○ Generous analgesics
○ Oxygen supplementation
○ Hydroxyurea – reduces the frequency of painful crises, but
has some associated risks
Patients with sickle cell disease should avoid ___ and ____
dehydration and hypoxia
When _____is possible before significant
organ damage, it can cure more than 80% of patients with Sickle Cell
Anemia who have suitable matched donors
allogeneic Bone Marrow Transplant
What should you recommend to patients who are heterozygous carriers (sickle cell trait)
Genetic counseling
With supportive care, average life expectancy for sickle cell disease is now between ____ years of age
40-50
Thalassemias are hereditary disorders characterized by ____
reduction in the synthesis of globin chains (alpha or beta)
Reduced globin chain synthesis causes reduced hemoglobin creation and
a ____ because of defective
hemoglobinization of RBCs
hypochromic microcytic anemia
T/F The inheritance pattern of Thalassemia is not straightforward, being autosomal
dominant for some and recessive for others
T
Thalassemia overall is most common in families from ____
southeast Asia and China, the Mediterranean area, and those of African descent
Alpha-Thalassemia:
Due to complete loss of one or more of the four
copies of the alpha-globin chain gene
Alpha- thalassemia levels
○ Loss of 1 - Silent carrier (asymptomatic)
○ Loss of 2 - Alpha-Thalassemia trait (“minor-thalassemia”)
○ Loss of 3 - “Alpha 3”
■ Severe anemia with signs of hemolysis – requires treatment
○ Loss of 4 - Hydrops fetalis (death in utero)
■ No normal alpha hemoglobin is produced
