Qualitative Hemoglobinopathies

Question 1

Sickle Cell Disease

Answer 1

Homozygous
Hgb S has decreased oxygen affinity and impaired oxygen transport
Spleen sequesters the sickled RBCs
Less severe when paired with alpha thalassemia

Question 2

Sickle Cell Trait

Answer 2

RBCs can still sickle under very low oxygen tension

Question 3

Hemoglobin C Disease and Trait

Answer 3

Splenomegaly and joint pain

See codocytes and Hgb C crystals

Question 4

Hemoglobin SC Disease

Answer 4

Occurs when heterozygous for both Hgb C and S mutations
Mild to moderate anemia is present
Manifests like a mild sickle cell disease

Question 5

Hemoglobin D Disease (Los Angeles)

Answer 5

Possible with HgbS and Beta Thal, but rare

Homozygous Hgb D is rare and causes mild hemolytic anemia

Question 6

Hemoglobin E Disease

Answer 6

Causes an asymptomatic microcytic hypochromic anemia

See codocytes

Question 7

Hemoglobin M (Methemoglobinemia)

Answer 7

Blood appears brown

Caused by iron changing from 2+ to 3+