Hemoglobinopathies

What is a Hemoglobinopathy?

abnormally formed or diseased hemoglobin

What does Anemia mean?

decreased oxygen-carrying capacity of red blood cells

All the hemoglobinopathies cause _____

Anemia

Is Thalassemia an acquired or genetic disease?

Genetic, can only be inherited.

What is Thalassemia?

- disease of hemoglobin production due to atypical genetic coding for the globins in hemoglobin

- there is alpha and beta thalassemia

Alpha Thalassemia

genetic coding that causes reduction in Alpha globin

What occurs when someone has Alpha Thalassemia?

- die in utero (missing all 4 alleles)

- severe anemia

- mild microcytic anemia

- sometimes no anemia at all

In Alpha Thalassemia, since there is reduced alpha goblin, what occurs to existing beta goblins?

form unstable tetramers called Hemoglobin H which do not work as efficiently as the typical Hemoglobin A

Beta Thalassemia

genetic coding that causes reduction in Beta globin

What occurs when someone has Beta Thalassemia?

- major form= profound anemia and require transfusions to survive

- minor form= microcytic anemia but typically asymptomatic (may not even know they have it)

What is the most common anemia in the USA?

iron-deficiency anemia

Both Beta thalassemia minor and Alpha thalassemia trait both can be confused with iron-deficiency anemia. Why?

- because all three conditions manifest with a microcytic anemia

- however pts with thalassemia should not take iron supplements!!

What's the major difference between Thalassemia and sickle cell disease?

- Thalassemia is a problem of globin production

- Sickle cell is a problem of globin shape changes

What causes Sickle-Cell disease?

autosomal recessive genetic modification of the beta globin gene

While sickle-cell is partially protective against malaria, why is it bad normally?

In hypoxic situations, the sickle-shaped RBCs can occlude small blood vessels causing vaso-occlusion.

What is Vaso-occlusive pain and why is this important to manage and know in regards to SCD?

- RBCs sickle in response to a trigger - which is often hypoxia. - sickling cells cause blocked blood flow in small blood vessels, which worsens the low oxygen problem because the oxygen-carrying blood cannot get to the tissues.

- the low oxygen tension also leads to hemolysis of the RBCs, worsening the anemia.

- tissue infarction, ischemia, multi organ failure and death can occur

What is Vaso-occlusive pain?

How do RBCs sickle and become misshaped?

beta globin gene has one point mutation that changes the shape of the beta chains. The beta chains will contort to rigidly flatten the RBC when triggered, usually by low oxygen.

Compare and contrast sickle cell disease and sickle cell trait.

sickle cell disease =

- carrying 2 recessive genes

- high risk for vast

- occlusive events

sickle cell trait =

- carrying 1 of the genes

- more common

- asymptomatic unless they have another globin mutation

Summarize the clinical features of thalassemia and sickle cell disease and the diagnostic tests used in its assessment.

Describe the medical management of thalassemia and sickle cell disease in general terms.

Create a perioperative dental treatment plan for a patient with sickle cell disease.