Over 5000 Canadians have Sickle Cell Disease; SCDAAC is working to raise awareness and support families living with Sickle Cell Disease in Nova Scotia

What is Sickle Cell Disease?
Sickle Cell Disease is a condition people can inherit; they are born with it. It is caused by an abnormality in a protein called hemoglobin. Hemoglobin is found in high quantities within the red blood cells. Its role is to carry oxygen from the lungs to all parts of your body, which keeps your vital organs working. Normal red blood cells are the most abundant cells in the blood. They have a round shape that looks like a doughnut. Red blood cells circulate smoothly in all blood vessels. The haemoglobin dissolves easily within the red blood cell (almost like sugar in water). In people with sickle cell disease, the body produces abnormal sickle cell haemoglobin, which causes the cells to take on an unusual shape. They then start sticking together, and not flow as smoothly.

The sickled red blood cells become stiff and less flexible than normal red blood cells, and can block blood vessels as they travel through the body. This can lead to many sickle cells complications such as severe pain and damage to organs. Sickled red blood cells are also more fragile and are destroyed by the body more quickly than regular red blood cells are, which leads to lower than normal hemoglobin levels (also known as anemia).

SCD patients may experience:

  • Severe pain episodes
  • Vulnerability to infection
  • Need for frequent blood transfusions

What causes Sickle Cell Disease?

SCD is a condition one may inherit from their parents. Along with eye and skin colour, the abnormal gene can be inherited along with their genetic material.

Are there different types of Sickle Cell Diseases?

The hemoglobin S gene is the most frequently inherited type of gene for sickle cell disease. Most affected individuals have two S beta-globin genes, also known as hemoglobin SS disease. The combination of one S beta-globin gene with another type of abnormal beta-globin genes such as beta-thalassemia, hemoglobin C, or other rare abnormal beta-globin genes (Hemoglobin O-Arab, Hemoglobin D-Punjab, etc) may also lead to sickle cell disease. Hemoglobin S-Beta thalassemia tends to be as severe as hemoglobin SS disease, whereas hemoglobin SC tends to be milder.

SCD is caused by a specific change to the beta globin protein, made by the beta globin gene. Genes are our body’s instructions for growth and development and are found in almost every cell in our body. They instruct our body to make proteins, which carry out various jobs in our body. Our genes are found on structures called chromosomes, like beads on a string. Our chromosomes come in pairs; one member of each pair is inherited from each parent. Our genes therefore also come in pairs. The beta globin gene is found on chromosome 11. Everyone has two copies of the beta globin gene. SCD is caused by a specific mutation in the beta globin gene. This mutation is written as Glu6Val.

SCD is a recessive condition. This means that in order for an individual to be affected with SCD, both copies of their beta-globin gene are not working properly.   In order for someone to inherit a condition like SCD, they would inherit one not-working copy of the beta-globin gene from each parent. Parents of an individual with SCD are known as carriers, as they carry one not-working copy of the gene. This means they have sickle cell trait. Their working copy of the gene is able to compensate for the loss of the not-working copy, and they are healthy. In a couple where both members are carriers, there is a ¼ or 25% chance with each pregnancy that the child will have SCD. There is a ¾ or 75% chance with each pregnancy that the child will be unaffected.

If only one member of a couple is a carrier of SCD, then their children are not at risk to inherit SCD. However, sickle cell trait can combine with other thalassemias/hemoglobinopathies and can result in clinically significant disease, depending on the combination. A referral to genetics to review what these changes might be, as they vary from case to case, can help sort this out.

We are all carriers of 5-8 different recessive genes but are not typically affected by them because we have one working copy as well. Being a carrier of sickle cell trait is very common in individuals who are from areas of the world near the equator, and especially in individuals of African-Canadian ancestry.

If an individual is a carrier of SCD, then each of their siblings has at least a 50% chance (1 in 2) of also being a carrier. Their siblings’ carrier status depends on the carrier status of their parents.   A hemoglobin electrophoresis can determine whether or not an individual is a carrier of SCD. If a person is identified to be a carrier of SCD, it is very important that their partner also be screened for all thalassemias/hemoglobinopathies. This is accomplished through a CBC and a hemoglobin electrophoresis on a blood sample. (Special thank you to the IWK for authoring the information and compiling the diagrams)

Healthcare – Information to Know
What sort of information should I ask to my healthcare provider about living with sickle cell disease?

  • Ask about the type of sickle cell disease that you and been diagnosed with
  • Discuss on how to encourage close relatives (parents and siblings) to also have themselves tested for sickle cell disease
  • If you have a partner and would like to have children, discuss how your partner should also be tested to determine your chances of having an affected child

If you are of South American, Indian, Mediterranean, Middle Eastern, African, or Caribbean heritage, please call your doctor to learn your SCD status.

Keys to Living Well with SCD – Good Health!

  • Eat healthy, unprocessed foods as much as possible
  • Drink enough water every day
  • Exercise
  • Regular check-ups with your doctor
  • Vaccinations and flu shots as advised by your doctor

What is Newborn Screening?
Newborn screening for sickle cell disease is a vital tool to ensure that babies born with this condition are identified and placed on life-saving treatments.

Since 1986, research evidence has been generated in support of the benefits of newborn screening for sickle cell disease. Early diagnosis accompanied by penicillin prophylaxis, appropriate vaccinations, and parental education is effective in preventing early mortality and severe morbidity in children born with this life-threatening disease. Newborn screening is the process of testing newborns for specific disorders. Shortly after a baby is born, a doctor or nurse takes a small blood sample from the heel of the baby’s foot. The sample is sent to a laboratory, where it is tested for a number of disorders. One of the tests may look for sickle cell disorder.

Importance of screening for SCD
Early diagnosis for sickle cell disease through newborn screening allows for immediate intervention and treatment. Early interventions have been shown to prevent early mortality and severe morbidity in children born with this life-threatening disease. It may reduce hospitalizations and increase life expectancy. Ultimately, newborn screening can lead to longer, healthier lives. Without newborn screening, newborns may suffer irreversible damage to health and without newborn screening; affected individuals may suffer recurrent infection, debilitating pain, anemia and chronic organ damage including stroke, kidney & respiratory failure.

Newborn screening through the expanded program in Nova Scotia was announced on April 1, 2014. The Maritime Newborn Screening Program at the IWK Health Centre is set up to perform sickle cell screening for all newborns in the province. Proactive measures such as these are essential in providing the most effective treatments for those with Sickle Cell Disease.