Could you have the disease?
Tanzania has the 5th highest incidence of SCD with 8000-11,000 babies born with the disease annually.
So what do Tanzanians Need to Know About the Sickle Cell Disease?
In simple terms, Sickle Cell Disease (SCD) is a blood disorder in which one’s red blood cells form into a sickle shape. A normal red blood cell is shaped as spherical/disc like, which means it can easily move through the large and small blood vessels to deliver oxygen throughout the body. Now when you have a sickled cell, it tends to carry less oxygen, die quicker and stick to walls on the blood vessels causing a blockage that slows or stops the flow of blood altogether.
This causes major complications in the body, including pain, swollen limbs, damage to the organs, anaemia to mention a few.
|Normal red blood cells||Sickle red blood cells|
|Contain hemoglobin A (Normal)||Contain Haemoglobin S (Abnormal)|
|Disc shaped||Sickle shaped|
|Soft and flexible||Hard and rigid|
|Easily flow through blood vessels||Often get stuck in small blood vessels|
|Live for 120 days||Live for 20 days or less|
So, could you have Sickle Cell Disease?
Fortunately/ unfortunately SCD is a purely inherited disease. Which means, you are born with it or not. SCD is not contagious.
A person cannot catch it or pass the disease to another person like a cold or infection. One cannot get SCD through mosquito bites as in the case of malaria either. SCD cannot be transmitted through physical contact, sharing food/utensils or through breastfeeding.
HOW DO YOU INHERIT THE DISEASE?
SCD is passed on from both parents. This means both the mother and the father must pass on the abnormal form of the gene (the Sickle Shaped Red Blood Cells) for a child to be affected. SCD is inherited from parents in the same way blood groups are inherited.
People who have SCD inherit two hemoglobin S genes, one from each parent. When a person has two hemoglobin S genes also known as Hemoglobin SS, the disease is called sickle cell anemia. This is the most common and often most severe kind of SCD.
For those that inherit only one gene from one parent (either mother or father), they are known to have Sickle Cell Trait.
What is Sickle Cell Trait?
As previously mentioned, a person who inherits one abnormal gene that can create Sickle Shaped Red Blood Cells is known to have Sickle Cell Trait, also referred to as a Sickle Cell Carrier. This one abnormal gene would not matter whether it is from the father or mother, it could be passed on either way.
The implications are that, most people that have the Sickle Cell Trait (are Sickle Cell Carriers) do not have any symptoms and generally appear healthy. They wouldn’t know they have the trait unless they got tested. However, these have the potential to pass on the disease to their children, given their choice of partner.
For those that still can remember their basic biology, the figure below is a detailed illustration of the different scenarios that affect how one inherits SCD or Sickle Cell Trait. For the shortened version, in a scenario for instance that a Man has Sickle Cell Trait (is a disease carrier) and his wife/partner has Sickle Cell Trait (is also a disease carrier), every time they have a child, they have a 50% chance of that child having SCD. Because this child could potentially inherit the Sickle Cell Gene from the father AND the mother.
This is how healthy looking parents end up having a child with SCD. Unfortunately, there is no formula to calculate how many SCD children or SCD carrier children the aforementioned couple can have, the same way one could not choose how many tall or short children they can have if the parents are short and tall.
Created: 01 March 2017