To understand what sickle cell disease is, we first have to know something about the composition of our blood cells. There are different types of blood cells. Some of these are red blood cells. These are the cells that help in distributing oxygen throughout the body.
In healthy individuals, these cells maintain a round shape that is flexible enough to move easily throughout all the blood vessels’ intricate network.
What is sickle cell anemia?
In sickle cell disease, the red blood cells cannot maintain their round and flexible shape. Instead, they have a tendency to lose this shape under certain conditions. They collapse and assume the shape of a sickle or a crescent moon. When this happens regularly, these cells become inflexible and cannot move easily through blood vessels.
Sickled red blood cells usually stagnate in the blood capillaries. When this happens, the blood supply to certain areas of the body (or parts of an organ) is greatly impaired. This leads to some tissues being starved of oxygen. This can lead to small parts of the starved areas dying due to a lack of oxygen.
This state can lead to increased physiological stress, which can further lead to more cells sickling, thus setting up a vicious cycle of events.
Signs and symptoms of sickle cell disease
The signs and symptoms of sickle cell disease can vary in presentation and severity in different people. Some people will remain symptomless for many years. Even in the same person, these can vary from one episode to another.
Common symptoms include:
- Anaemia. When cells sickle and get trapped in blood vessels, they usually break down (haemolyse). With time, this leads to fewer red blood cells (anemia).
- Recurrent pain. This occurs when the blood supply to certain areas is cut off.
- Nodes in the hands and feet are swollen and painful.
- Susceptibility to infections
- Stunted growth and development in some children
- swelling of the abdomen
Other less common symptoms include body heat and stroke, the occurrence of which is a sickle cell medical emergency.
How sickle cell disease is acquired
Sickle cell disease is an inherited disease. This means that the disorder is passed from the parents to their child. This occurs when an abnormal change happens in the gene that regulates the making of the hemoglobin part of the red blood cells.
In sickle cells, the hemoglobin is abnormal and does not support the integrity of the shape of a normal cell. This makes the cell collapse under certain stressful situations. This includes the normal physiological stresses of the body.
For a person to get sickle cell disease, he must inherit two defective hemoglobin genes from both parents. If both parents have sickle cell disease, then all their children will suffer from the condition.
Both parents may be what is referred to as “sickle cell trait” individuals. Here, they have both normal and abnormal hemoglobin genes. They are usually without symptoms, but they can pass the defective genes on to their children, who will develop sickle cell disease.
If the child receives one normal and one abnormal hemoglobin gene, then they become sickle cell trait victims. They will remain asymptomatic but face the risk of passing on the defective gene to their children.
To summarize the above explanation, here is an illustration of what would happen where both parents have sickle cell traits. That is, they have a pair of both normal and abnormal hemoglobin genes. Chances are if they have a child;
- The child has a 25% chance of inheriting normal hemoglobin genes.
- The child has a 50% chance of acquiring sickle cell trait status—one normal hemoglobin gene and one sickle cell hemoglobin gene.
- the child inheriting both sickle cell hemoglobin genes and hence developing sickle cell disease.
Sickle cell disease is a serious condition. Having said this, it is possible to live successfully with the disease despite all the accompanying life challenges.