42 Hemoglobin C (Hb CC) Disease
Michelle To and Valentin Villatoro
Cause(s):
β globin chain amino acid substitution in the 6th position from glutamic acid (Glu) to lysine (Lys).1,2
Inheritance:
Autosomal dominant1
Demographics:
West Africa1
Clinical Features:1-3
See Hemoglobin C under RBC inclusions for additional information.
Less splenic sequestration and milder chronic hemolysis compared to sickle cell disease. Patients are usually asymptomatic.
Laboratory Features:1,2
|
CBC: Hb: Decreased Hct: Decreased |
PBS: Normochromic, normocytic RBCs *Hb C crystals Target cells nRBCs |
BM: N/A |
|
Hemoglobin Electrophoresis: Hb S: >90 Hb A: None Hb A2: Normal Hb F: <7%
*Not always seen, more likely in patients who have had a splenectomy. |
Other Tests: Solubility Screen: Negative Metasulfite Sickling Test: Negative HPLC Hemoglobin Electrophoresis |
References:
1. Laudicina RJ. Hemoglobinopathies: qualitative defects. In: Clinical laboratory hematology. 3rd ed. New Jersey: Pearson; 2015. p.231–50.
2. Randolph TR. Hemoglobinopathies (structural defects in hemoglobin). In: Rodak’s hematology clinical applications and principles. 5th ed. St. Louis, Missouri: Saunders; 2015. p. 426-453.
3. Harmening DM, Yang D, Zeringer H. Hemolytic anemias: intracorpuscular defects. 5th ed. Philadelphia: F.A. Davis Company; 2009. p. 207-29).
