- Hemoglobin C (HbC) is an abnormal hemoglobin in which substitution of a glutamic acid with a lysine at the 6th position of the β-globin chain
- This mutation is either heterozygous or homozygous, In heterozygous condition, one HbC gene from parents coming so the there is about 28–44% of total hemoglobin (Hb) is HbC, and no anemia develops. while In homozygotes, nearly all Hb is in the HbC form, resulting in mild hemolytic anemia
People with hemoglobin C do not have Hemoglobin C disease or sickle cell disease. They cannot develop these diseases later in life. They can pass hemoglobin C trait to their children.
People who have hemoglobin C disease have red blood cells that contain mostly hemoglobin C
How is Hemoglobin C Trait inherited ?
If one parent has hemoglobin C trait and the other parent has normal hemoglobin, there is a 50 percent (1 in 2) chance with each pregnancy of having a child who has hemoglobin C trait.
How is Hemoglobin C Disease Inherited?
If both parents have hemoglobin C trait, there is a chance of having a child with hemoglobin C disease
Hemoglobin C and S condiftion (Hb SC)
- Individuals with sickle cell–hemoglobin C (HbSC), have the gene for HbS inherited from one parent and the gene for HbC is inherited from the other parent. The peripheral smear demonstrates mostly target cells and only a few sickle cells.
- There are fewer acute vaso-occlusive events. However, persons with hemoglobin SC disease (HbSC) have more significant retinopathy, ischemic necrosis of bone, and priapism than those with pure SS disease.
Hemoglobin SC disease
Dark red, blunt and often curved crystals, usually with 1-2 fingerlike projections
Composed of Hemoglobin SC
How is Hemoglobin SC Disease Inherited?
Hemoglobin SC Disease Inheritance
Hb C Dieases and Trait Symptoms:
- Hemoglobin C Trait (Hb AC) – no anemia develops (no symptoms)
- Hemoglobin C Disease (Hb CC) – mild hemolytic anemia, mild spleenomegaly, jaundice and pigmented gallstones might develop
Epidemiology
- About 1 out of every 40 African-Americans has hemoglobin C trait.
Laboratory Diagnosis of Hb C Disease
- CBC (Complete Blood Count)
- Peripheral Blood Smear ( Target cells, Hemoglobin C Crystals, Microspherocytes)
- Hemoglobin Electrophoresis
Hemoglobin C Crystals and Target Cells
Treatment
- no treatment needed except folic acid supplementation
Reference:
http://colleges.weber.edu
http://www.stjude.org/stjude/v/index.jsp?vgnextoid=f1b0db6324d6f110VgnVCM1000001e0215acRCRD
http://en.wikipedia.org/wiki/Hemoglobin_C
