Sickle Cell; An avoidable disease?

UTG Medical Students’ Association

Ousman and Zainab were high school sweethearts. They were very much in love and their love blossomed as they grew and went further in life. One day, Ousman went to his best friend Lamin to seek his advice on the idea of marrying Zainab whom he loved dearly. Lamin agreed but added, “ndo I think it’s important that you both check your genotypes deh, remember what we were taught in high school about sickle cell, nyom SS and AS?” Ousman replied,” boy Lamin bai ma, sickle cell has nothing to do with my love for Zainab. Bulma disturb, love ak commitment is all that matters” but Lamin kept on insisting and since he saw his friend was unrelenting, he let go of the idea and gave his best wishes to his friend on their marriage.

One year later, Ousman and Zainab welcomed the birth of their daughter Aisha. She was a wonderful bundle of joy to the family but 6 months after her birth, Aisha become a great worry to her parents. She developed painful swelling on her hands and feet, yellowish eyes and skin, and became easily irritated, weak, and always uncomfortable. Her parents became worried and decided to take their daughter to the hospital for help where Aisha was diagnosed with sickle cell Anemia. Ousman and Zainab were shocked, confused, and wondered how their daughter got such a disease. The doctor asked them if they checked their genotypes before marriage because they must have both been carriers of the disease for Aisha to have it. Ousman remembered the advice of his friend and begged the doctor to know more about such disease…

What is sickle cell disease?

Sickle cell disease is an inherited disease that affects red blood cells. It is inherited in an autosomal recessive pattern, which means that each parent has copies of the sickle cell gene but does not show signs and symptoms of the condition. It is said to affect about 50 million people worldwide.

Normally, the red blood cells are shaped like discs and flexible enough to travel through even the smallest of blood vessels, thus carrying oxygen to all body parts. In sickle cell disease, the red blood cells become hard, and sticky and are “C” shaped or resemble a “sickle” (a farming implement used to harvest cereals). This makes it difficult for these cells to flow freely along the blood vessels. Pains and other complications may result from this.

How many people are affected?

About 50 million individuals worldwide are living with the disease. Also, about 300,000 children worldwide are born each year with a new diagnosis of sickle cell disease. According to WHO, most children with sickle cell anemia pass away before the age of five, typically due to an infection or severe blood loss. It is said to affect people of African, Mediterranean, and Middle East descent.

Causes of sickle cell disease

Sickle cell disease is caused by inheriting the sickle cell gene. It is not caused by anything the parents did before or during the pregnancy so it is a non-communicable disease. You inherit one set of genes from each parent since genes naturally come in pairs(diploid).

 In order to be born with either form of sickle cell disease, one must inherit both sickle cell genes from the mother and father. A person is said to be a “carrier” of the disease if only one parent passes the sickle cell gene to the person. Sickle cell carriers do not themselves have the disease (as was the case with Ousman and Zainab), but they run the risk of passing the disease on to their progeny. If a carrier has a child with another carrier, there is a 1 in 4 or 25% chance that the infant will have sickle cell disease.

Forms of sickle cell disease

There are different forms of sickle cell disease. People with the disease inherit genes that code for abnormal hemoglobin. This affects the red blood cells and oxygen transport; hemoglobin is the iron component found in red blood cells that aids oxygen transport to the tissues.

The different forms are:

1.         Hemoglobin SS disease: This is the most common type of sickle cell disease found in most parts of Africa, Gambia included. People who have this form inherit two genes, one from each parent that codes for hemoglobin “S.” This form is commonly called sickle cell anemia and is the most severe form.

2.         Hemoglobin SC disease: A person with Hb S/C illness has two different types of defective hemoglobin in their red blood cells (RBCs).

3.         Hemoglobin SB+(beta) thalassemia, Hemoglobin SD, hemoglobin SE, and hemoglobin SO: These forms of sickle cell disease are rare with mild symptoms.

Symptoms of sickle cell Anemia

The signs and symptoms of sickle cell Anemia might vary from person to person and can start to develop as early as 6 months of age.

1.         Anemia: Red blood cells typically last for 120 days before needing to be replaced, however, sickle-shaped red blood lose their viability easily. They normally die in 10 to 20 days leaving a shortage of red blood cells known as anemia. Due to a shortage of red blood cells, the body cannot receive adequate oxygen, which wears down the body’s cells.

2.         Painful episodes: These are commonly referred to as “sickle cell crises” and can be quite severe lasting anywhere from a few hours to a few days. Periodic episodes of extreme pain are a major symptom of sickle cell anemia. Blockage of blood flow in some parts of the body such as the joints, abdomen, and chest causes the pain to develop. While some people only experience a few pain crises a year, others do so more frequently. A serious pain emergency can necessitate a hospital stay. It is not exactly clear what triggers the pain but sometimes it could be caused by changes in weather conditions (such as cold, wind, or rain), dehydration stress, or excessive exercise.

3.         Elevated infection risk: Infections are more likely to affect people with sickle cell anemia, especially when they are young. This is due to damage to the spleen by sickle cells. For children under the age of 5, infections are the leading cause of death. This is due to the destruction or damage of the spleen by sickle cells. Vaccinations and antibiotics can help lower the risk of many infections.

4.         Yellowing of the eyes, skin, and mouth: Jaundice is a common sign and symptom. As a result of sickle cells’ shorter life span than normal red blood cells and the liver’s inability to filter them quickly enough, bilirubin- the substance responsible for the yellow coloration, accumulates in the body leading to jaundice.

There are several other symptoms like;

o          Swelling of hands and feet

o          Delayed growth or puberty

o          Vision problems

and even chronic symptoms like stroke, acute chest syndromes, and leg ulcers.

Diagnosis of sickle cell Anemia

In the Gambia, a number of tests are performed to identify sickle cell anemia. Peripheral blood smear tests, Hemoglobin electrophoresis, and sickling tests are performed.

1.         Peripheral blood smear: This type of test involves collecting blood samples and viewing the number and shape of red blood cells in the blood using a microscope. It is carried out in a laboratory and provides data on the number and kinds of white blood cells, the quantity and kinds of abnormally shaped red blood cells, as well as a rough estimate of white blood cell and platelet count.

If the red blood cell’s shape and size deviate from normal and are elongated with tapered ends, then the patient is said to have the disease.

2.         HemotypeSC Test: A little drop of blood is all that is needed for the Hemotype sc test, and it’s a quick method for identifying the type of hemoglobin in whole blood.

3.         Hemoglobin electrophoresis: This is also used and it measures the hemoglobin levels in red blood cells and searches for any abnormality in hemoglobin types.

Treatment

There is no definitive treatment for sickle cell disease but there are supportive treatments which includes;

o          Pain control: Since pain is a typical symptom of sickle cell disease, pain control is a crucial component of therapy. Acetaminophen, opioids, and nonsteroidal anti-inflammatory medicines (NSAIDs) are a few examples of painkillers that can be used to control pain.

o          Blood transfusion: Transfusions of blood can help the body produce healthier red blood cells, which improves oxygen supply and lowers the chance of problems like a stroke.

o          Hydroxyurea: The disease-modifying drug, hydroxyurea can help lessen the frequency and intensity of painful crises as well as the requirement for blood transfusions. It functions by boosting the creation of fetal hemoglobin, which can lower the blood’s concentration of sickle hemoglobin.

o          Bone marrow transplant: A bone marrow transplant may be able to treat sickle cell disease by swapping out the patient’s damaged bone marrow with healthy bone marrow from a donor. However, this course of treatment is difficult and fraught with danger.

o          Gene therapy: This is an experimental medical procedure that alters a patient’s own cells to create healthy hemoglobin. This medication is still in its early stages and is not yet readily accessible.

It is important for people with sickle cell to work together with their healthcare provider to create a treatment strategy that addresses their unique needs, enable them to control their symptoms, and reduces the likelihood of complications.

Conclusion

It is very important to seek a genetic counselor to check and confirm genotype before trying to marry and conceive. Also if one carries the sickle cell trait, it is also important to seek a genetic counselor to help one understand the risk of having a child with sickle cell anemia. The counselor can explain the different preventive measures, possible treatments, and management of the disease. Don’t be like Ousman and Zainab who ignored the advice of their friend till it was too late. Get screened for the trait earlier to prevent unwanted outcomes.