Sickle Cell Disease is an inherited blood disorder that affects Red Blood Cells. People with Sickle Cell Disease have Red Blood Cells that contain haemoglobin S, an abnormal type of haemoglobin.
Haemoglobin is the substance within Red Blood Cells that carry oxygen from the air into our lungs and to all parts of the body.
Normal Red Blood Cells contain haemoglobin A. These are soft and disc-shaped and can squeeze through tiny blood vessels. They usually live for about 120 days before new ones replace them.
People with Sickle Cell Disease make a different form of haemoglobin called haemoglobin S. Red Blood Cells containing mostly haemoglobin S are stiff, distorted in shape and have difficulty passing through the body’s small blood vessels. They also have a shorter lifespan (about 16 days) than normal Red Blood Cells.
When sickle-shaped cells block small blood vessels, less blood can reach that part of the body.
Tissues that do not have normal blood flow eventually become damaged.
Globally, 300 to 400 thousand babies are born with Sickle Cell Disease each year, more than half of whom are in Sub-Saharan Africa.
Sickle Cell occurs in about 1 in every 500 African-American births, and about 2 million Americans or 1 in 12 African Americans carry the sickle cell trait.
Thirty percent (1 in 3) of Ghanaians have the Sickle Cell trait, and 2 percent of children born in Ghana annually have Sickle Cell Disease.
Sickle Cell is inherited from parents in much the same way as blood type, hair colour and texture, eye colour and other physical traits. The types of haemoglobin a person makes in the Red Blood Cells depend upon what haemoglobin genes the person inherits from his or her parents. Like most genes, haemoglobin genes are inherited in two sets, one from each parent.
If one parent has Sickle Cell Anemia (SS disease) and the other is Normal (AA), all of the children will have sickle cell trait (AS).
If one parent has Sickle Cell Anemia (SS) and the other has Sickle Cell Trait (AS), there is a 50% chance of having a baby with either Sickle Cell Anaemia (SS) or Sickle Cell Trait (AS) with each pregnancy.
When both parents have Sickle Cell Trait (AS), they have a 25% chance of having a baby with Sickle Cell Disease with each pregnancy.
Types of Sickle Cell Disease:
There are several types of Sickle Cell Disease. The most common are:
Haemoglobin SS Disease – Sickle cell anaemia.
Haemoglobin SC Disease.
Sickle Beta-Plus Thalassaemia.
Sickle Beta-Zero Thalassaemia.
Written by The Sickle Life Editorial Team
(The writers are persons living with Sickle Cell Disease and Sickle Cell Disease Advocates from Sickle Life. All Views expressed are personal, please contact your doctor/counsellor for further information.)