Hereditary spherocytosis:

- Cause

- Resulting defect

- Symptom(s)

- Lab findings

Cause: Defect in RBC membrane proteins like ankyrin and spectrin

Result: small round RBCs, no central pallor

Symptoms: splenomegaly and anemia

Labs: Positive osmotic fragility test

G6PD deficiency:

- Cause

- Resulting defect

- Symptom(s)

- Lab findings

Cause: X-linked defect in G6PD causes decresed glutathione

Result: increased RBC susceptibility to oxidant stress (like from sulfa drugs, infections, fava beans)

Symptoms: back pain, hemoglobinuria, anemia

Labs: Heinz bodies and bite cells on blood smear

Pyruvate kinase deficiency:

- Cause

- Resulting defect

- Symptom(s)

Cause: Autosomal recessive defect in pyruvate kinase causes low ATP

Result: rigid RBCs

Symptoms: Hemolytic anemia in a newborn

HbC defect:

- Cause

- Resulting defect

- Symptom(s)

Cause: Glutamic acid to lysine mutation at position 6 in chain mutation

Result: HbSC

Symptoms: milder form of sickle cell anemia

Paroxysmal nocturnal hemoglobinuria:

- Cause

- Resulting defect

- Symptom(s)

- Lab findings

Cause: Impaired synthesis of GPI anchor/decay-accelerating factor in RBC membrane

Result: Complement mediated RBC lysis

Symptoms: bloody urine at night/morning, thrombosis

Labs: increased urine hemosiderin

Sickle cell anemia:

- Cause

- Resulting defect

- Symptom(s)

- Lab findings

Cause: HbS point mutation in β chain substituting glutamic acid with valine at position 6

Result: Deoxygenated HbS polymerizes

Symptoms: Low O₂ or dehydration precipitates sickling causing anemia and veno-occlusive disease

Labs: "crew cut" skull on x-ray from marrow expansion

Autoimmune hemolytic anemia:

- Cause

- Lab findings

Cause: warm or cold agglutinin autoimmune anemia

Labs: Coombs' positive

Microangiopathic anemia:

- Cause

- Resulting defect

- Lab findings

Cause:Narrowed vessel lumens damage RBCs

Result: hemolytic anemia

Labs: Schistocytes seen on blood smear

Macroangiopathic anemia:

- Cause

- Resulting defect

- Lab findings

Cause: prosthetic heart valves and aortic stenosis damages RBCs

Result: hemolytic anemia

Labs: Schistocytes on peripheral blood smear

Warm agglutinin autoimmune anemia:

- What causes it

- Duration

- 3 pathologies in which it can be seen

Cause: IgG

Duration: chronic

Situations: SLE, CLL, certain drugs

Cold agglutinin autoimmune anemia:

- What causes it

- Duration

- 3 pathologies in which it can be seen

Cause: IgM

Duration: acute

Situations: CLL, Mycoplasma pneumonia infection, or infectious mononucleosis